Here are the schematics and layouts for the Hand Substrate Interface! After prototyping, a schematic was sketched out onto a sheet of paper. Through some configurations with the help of Fritizing, an open source hardware application for virtual breadboarding, a schematic was created using Adobe Illustrator to visualize the circuit and components. From there, the circuit was then transferred to the layout on the glove to figure out placement. This was useful in identifying where the place components on the wrist and how to connect the various inputs to the correct pins on the microcontroller.
This post marks part 3 (?) of the Hand Substrate Interface to be used to test for soil moisture.
To use the Hand-Substrate Interface, the user interacts with the glove in order to obtain the reading. A reading is only taken when the user wants to measure the soil moisture level, as opposed to obtaining a constant feed regardless of the hand placement. This will conserve battery life while out on a foray along with making sure that the data collected is accurate of the substrate condition. In order to understand this experience, the interaction between the glove and the user has been storyboarded to see this data collection process.
The storyboard is as follows: The user is on a foray and moves through the woods when they spy a lone mushroom specimen growing on the forest floor. She kneels down next to the mushroom to get a closer look, making note of the surroundings, along with making initial identifications of the mushroom. The user then pushes a button on the HSI in order to let it know that she needs to take a reading. Seeing the interface respond, she then takes the soil moisture reading with her hand, taking note of the reading. From this reading, she sees that the ground in this area is much more moist than an earlier area of the walk. Looking around to get a idea of the level of the ground, the user wonders if this is because the ground is at a lower topographic height which would collect more water. She looks up to see the density of the foliage overhead and wonders if the increase in tree canopy has created a barrier for the soil moisture to evaporate, thus leading to an increase of mushrooms cropping up in the area. As the user ponders these environmental questions, this data captured from the reading which includes the moisture reading, GPS location and timestamp is then stored in the glove. After the walk, she will extract this data from the HSI and upload it to her local mycological club’s online database where she can compare walks this data to what other members have collected.
Since a reading is only taken when the user wants to get the soil moisture level as opposed to obtaining a constant feed, the interaction between the user and the glove needs to be designed in order for the user to obtain the reading as needed. An RGB LED interface is used on the glove in order to display the various states of the gloves to the user. A Neopixel 12 – LED ring is being utilized as this display because of its compact size and circular features. Less than 2 inches in diameter, the Neopixel is able to lie flat on the back of the hand or elsewhere on the arm. The circular nature of the LEDs also allows to function as a dial when getting a reading. This ring formation also gives way for placement of a momentary switch that the user can press to cycle through various states of the circuit to interact with the HSI. The use of RGB LEDs and programmability of the Neopixel ring gives flexibility in a range of designs and patterns that can be used to communicate these different states.
While the user is walking through the woods, the ring is turned off, with no LEDs on. Only when the user needs to take a reading will she press the switch located at the center of the ring. Upon being touched, the ring will light up, indicating that it is now turned on. When the user is ready to take a reading, they will press the button again, whereupon a pulsing light with yellow LEDs blinking off in succession four at a time which will indicate the countdown for a reading. With the 12 LEDs on the ring, this will indicate a three second countdown. While this is happening, the user will have time to place their fingers in the soil to ready themselves for a reading. After the blinking countdown, the ring of lights will now function as dial, showing the moisture of the soil based on how many blue lights are turned on going in a counter clockwise direction starting from the bottom center of the ring. This reading may fluctuate if the user is moving while taking the reading, but when it senses that there is no change after a few seconds, the reading is then stored, shown by a blinking green light. The user may now take an additional reading if desired, or continue on their foray. If the HSI senses no activity after a short period of time, the system will go to a battery conservation mode, indicated with the lights powering off.
This interaction is simple in indicating to the user what state it is in order to allow for ease of use. Although the reading does not give the user a numerical value, the dial will give the user a visual sense of the reading, which can be compared with other readings taken during the foray. This design choice was made in order to keep the user focused on the process of the walk, rather than have to compare the actual numbers. Rather than presenting the data points as hard values, the dial indicator for the soil moisture reading acts as a suggestion and reminder for the user to question and compare the readings at other points of the walk. The data containing the actual numerical values however, can be stored and analyzed at a later time. Through use, the user may also develop a different sense of reading and using the HSI as she gains experience with the interaction of getting a reading through her fingers.
In prototyping this interaction, a soft momentary switch was built to use with the Neopixel ring. The momentary switch is made using two pieces of neoprene with copper conductive fabric adhered on one side using fusible webbing. The button is designed to be the same size as the Neopixel ring so that the ring can sit ontop of the button in the glove design. On one of the neoprene pieces, another piece of neoprene cut in a ring is attached on top of the copper fabric to prevent the two copper fabric pieces from constantly touching. The neoprene pieces are then hand sewn together to form the button. Only when the button is pressed down upon, will the two conductive fabric pieces make contact and read as a button press. A pull up resistor is added the switch so that the reading of the switch will constantly be read as “high” until button is pressed. The code for the program was written in Arduino using parts of the Neopixel library and combined with a previously written program for a soil moisture sensor that was adapted from the GardenBot project.
In considering other materials that can be used to build the gloves, leather was utilized in the third iteration of the glove design. Though it can be difficult to sew, leather can be more comfortable against the skin, provide structure for the form of the glove, along with being a durable material. Although leather is a material commonly used for making gloves, the nature of wearing another’s skin to enabling the wearer’s ability to sense the environment is also a bit fascinating. Given that this project overall advocates for facilitating new relationships between humans and other nonhuman agents, it is noted that only waste scrap leather was used from this project that was obtained from a wholesale resale fabric store in the Fashion District in Los Angeles.
In this iteration, the finger pieces are semi-detached from the hand in the glove. The leather is used to create a cap that sits on the fingertips where the exposed traces sit to take a reading. A mesh fabric harvested from a laundry bag was used for the underside of the finger cap so that as the sensors are placed in the soil, the user is also able to feel the ground through the mesh fabric. To attach to the rest of the glove, traces are made out of conductive spandex zig-zagged stitch to a cotton jersey material to create connections from the finger caps. On the back of the hand, a circuit is laid out to for the soil moisture sensor, Neopixel ring and the momentary switch.
The glove will then be attached to a wristband that will house the microcontroller, battery and other electronic components to form the circuit. Spreading the circuit out along the hand onto the arm prevents any bulky areas from forming that might get in the way of wearability. Splitting the circuit into different sections would also allow the circuit to be more accessible if there are any errors. The creation of the wristband also provides a platform for the addition of other components and features in future iterations. For example, the current demo prototype does not include the GPS module or a soil temperature sensor. However, the wristband would allow for placement of more components that could be added to the Hand-Substrate Interface.
While working on the conductive temporary tattoos, a wearable glove prototype is being concurrently developed. While wearing a glove creates a barrier for the hand to be immersed in the environment (ie: fully touching the soil), building the sensors onto the glove also allows for a device that can be used repeatedly. Flexible materials along with techniques for e-textiles can also be utilized to create traces that can sit on the fingers comfortably and that are robust enough to withstand the movement of the fingers from bending.
Other glove projects, such as the mi.mu project and the Flora MIDI drum glove, feature built in components into a glove. They offer interesting insights on how materials and components can be situated in the structure of the glove. For example, the mi.mu uses channels on top of each finger to house the bend sensors so that they are held close to each finger but held securely in place. The microcontroller, components and battery are held in a separate wrist band which can be connected to the rest of the glove, allowing for easy removal and attachment from the bend sensor elements.
The Flora MIDI drum is a project that uses the drumming of the fingers against the surface to play synths. In this project, with accompanying tutorial, piezos are attached to the fingertips of a preexisting glove. These pieces are then attached and soldered to a wearable microcontroller attached to the the back of the glove. Although this piece needs to be plugged into a computer to generate the tones, it provides insight in how the surface of the glove can be embedded with electronics.
However, unlike my glove project, neither of these deal with working directly in a natural environment. In both instances, these gloves are used for musical performance in which the musician or performer wears the glove and uses the gestures of their hand and fingers to compose and form the music. In the case of the Hand-Substrate Interface needs to be able to interact with the substrate, mostly earth in this case to get a reading. As a result this glove needs to be produced with that interaction in mind in regards to sensor placement and material choices.
In the first image of this post, the initial glove prototype can be used fairly effectively in order to sense soil moisture. Using a gardening glove, two exposed traces made out of conductive fabric are fused to the tips of the index and middle finger using heat-fusible webbing. These trace are then connected to wires which are connected to the surface of the glove using couching, an embroidery technique. With couching, a piece of thread is used to sew around a thicker piece of thread, wire in this case, by stitching around it in equal intervals. This allows for the wire to become attached to the surface while retaining the flexibility. As an initial proof of concept, this glove is effective in obtaining soil moisture readouts. However, the thickness of the glove can create discrepancies in the soil reading and the heavy rubber coating at along the fingertips also can mask the user’s interaction with the soil. This prototype also relies on a separate breadboard and a laptop in order to see the output of the sensor. In these series of prototypes, a custom glove is patterned and designed in order to make a glove that can sit closer to the hand, along with using materials that can allow for environmental interactions. Designs are also considered in how the hardware and output can be housed directly on the hand.
A custom pattern was created for the glove by utilizing a low-fi patterning technique. A latex glove was worn as a base, while painters tape was applied in strips to cover the exterior. Since the thumb is currently not being used in the final glove, it was omitted from taping, though the other fingers besides the index and middle were covered in case the pattern needed to be modified to account for those fingers. Essentially by covering the latex glove with tape, a casted model of the hand is produced. After covering the glove, a seam was cut off the side in order to free the glove and tape from the hand. Tracing from the fingertip to finger, the fourchette, the part of the glove that gives depth to the each of the fingers is cut out. The taped glove can then be splayed and traced to provide a custom master pattern for producing the prototype.
Once the master pattern is traced, modifications can then made by using tracing paper to change features of how the glove is constructed. For example, traces can be drawn in, along with determining which regions of the glove can be sewn out of different materials.
The first prototype using the glove pattern was to test out the pattern, along with integrate some different materials into the piece. The “fingernail” area was constructed out of copper taffeta fabric to provide conductive traces, while a mesh netting was used in the bottom and top of the fingers. The fourchette was cut out of a black knit jersey material in a polyester blend, while the palm area was made out of a jersey polyester blend that had cut out details. An 1/8″ seam allowance was added to all the pattern pieces in order to make sure that the glove would still be true to the pattern with all the additional piecing happening at the finger areas.
In constructing the glove, the copper material was first sewn to the mesh netting to complete the top of the finger. The fourchette was then sewn to connect the top of the fingers to the back. In later iterations, it would be advised to sew the fingers to the rest of the glove before sewing them to the fourchette. This would allow for better shaping to occur at the base of the fingers, rather than the puckering that happened when sewn after connecting it to the fourchette. Once the top and bottom hand panels were sewn onto the finger pieces, they were seamed at both sides to create the tubular form for the hand. After sewing all the pieces together, extra material was trimmed off that was covering parts of the ring and pinky finger to allow for less constricted movement. Any fabric that was not sewn into a seam was then finished using a rolled hem to prevent fraying.
This prototype proved to be a fairly successful attempt in satisfying the original goals. This first prototype created a glove that fit well on the hand even when constructed out of different materials. Although there were some fit issue along the middle finger, this may be due to the difficulty of sewing the fourchette onto the fingers given that there are a lot of tight curves that need to be made in order to fit the finger pieces. One other issue with the prototype was the use of the conductive fabric in the “fingernail” region. While this design fits with the anatomy of the hand, the proximity of the two conductive areas do touch when the fingers are placed close together and may compromise the reading of the sensor. Going forward with a second prototype, this issue was taken into consideration when constructing the traces.
The second prototype for the glove addresses some of the issues in the first glove, including the fit around the finger and how to embed the traces into the glove. This version also used a modification of the pattern to create an open palm area.
To create the traces for this prototype, two strips of conductive spandex were first sewn onto the top of each of the finger pieces using a zig zag stitch. By using a zig zag stitch, this ensured that both of the pieces would be adhered together but retain the stretchiness of both fabrics. One of the main challenges of this prototype is placing these traces on the finger, as seen in other iterations of the Hand-Substrate Interface using the conductive temporary tattoos. The movement created by the fingers makes it challenging to rigid materials while allowing the hand to also not be completely shrouded by the material of the glove. An extra 1/2″ segment of the conductive spandex was left at the end of the fingers so that it could be sewn around the tip of the fingers after the glove has been assembled.
The mesh netting is now used for the bottom of the fingers so that when making contact with the earth, the traces will produce a readout of the ground while the bottom of the hand will be more exposed to the soil based on material choices.
In this prototype, a velcro closure is attached to for the panel around the thumb so that it can be more easily worn with the potential for adjustment. In contrast to the temporary tattoo piece which is a one time use, the glove version will be able to be used multiple times and thus considerations are being made on the overall wearability of the piece.
This post is a continuation of a previous one regarding building a conductive tattoo for my interface.
In building a conductive temporary tattoo following the DuoSkin paper, I realize that there was a difference in thinking how the circuit needed to function for the soil sensor circuit. In order to read the resistance between the two fingers in the soil, parts of the traces need to be exposed in order to get the reading. However, the circuit that is created by the tattoo is insulated, covered by either adhesive or the silicon base of the temporary tattoo paper. As an experiment to try to create exposed circuits that would stick to the stick, I tried different types of base adhesive to see how the gold leaf could be applied to the surface. Tutorials from makeup blogs shows that eyelash glue for applying false eyelashes or petroleum jelly could be utilized to hold gold leaf to the skin.
In this image, I have applied a thin layer of eyelash glue to my ring finger. The tube for the eyelash glue made it easy to squeeze a thin straight line onto my finger. On the other hand, applying the petroleum jelly was trickier since it was hard to tell if I was applying a straight and uniform line to my finger. I used a cotton swab to put a thin coat on my pinky finger.
This image shows a few experiments with creating different traces that can be worn on the body. The pinky uses petroleum jelly as an adhesive to hold the gold leaf onto the skin. On the ring finger, eyelash glue is used to hold gold leaf onto the surface. Then on the middle finger, I used some conductive paint by Bare Conductive, and finally on the index finger, I went for a combination of using petroleum jelly to hold gold leaf to my finger nail and then using the conductive tattoo as a trace connecting the nail to the finger.
For a base adhesive, eyelash glue worked better than the petroleum. The petroleum jelly was effective in holding the gold leaf to the skin, however the greasiness of the jelly caused it slide around. The eyelash glue on the other hand dries very quickly so the gold leaf needs to be applied soon after putting down the glue in order to create a bond that can last.
For the conductive paint, there was a high resistance across the short trace, a property of this conductive paint that can make it difficult to be used across a distance. With the temporary tattoo and petroleum piece, it was an interesting way to consider exposed and insulated parts of the trace, though it was hard to apply the two pieces in order to have the connect the two pieces.
Overall, one issue with making the exposed trace was to keep the pieces from flaking or falling off through use. Placing traces on fingers also pose a particular challenge because the traces would then need to be flexible and robust enough to bend and move with the fingers. The benefit of the insulated trace allows it to be secured to the skin, making it more robust, especially along the fingers, however cracking did occur after awhile through normal bending of the finger.
In referring to DuoSkin’s research and other work with conductive skin traces, most of the pieces were adhered to flatter places on the body away from joints such as the forearm, chest, upper arm or back. Applying the conductive traces to the fingers for this project is still a challenge in determining how to create a temporary circuit that can reside on these jointed sections and how to create both exposed and insulated traces. However, pursuing this research may allow us to understand how these circuits can be worn on different parts of the body, allowing for other types of interactions such as environmental sensing.
Since conceptualizing the shoe that takes in soil samples, I have taken steps to implement this idea into an object.
In looking at precedent works, there are a wide range of projects that have embedded technology into footwear. A common thread throughout these projects is that the functionality of the shoe depends on the movement of the wearer in order to actuate it.
The Nanohana Heels is a project by artist Sputniko! in collaboration with shoewear designer, Masaya Kushino. This pair of shoes was developed in 2012 following the Fukushima Daiichi nuclear disaster in Japan during Spring of 2011. As demoed in a video about the shoe, with each step into the earth, rapeseeds (nanohana in Japanese) are dispensed from the stiletto point of the heel. According to Sputniko’s website, Belarusian scientists have determined that rapeseed blossoms are able to absorb radioactive substances. This research was done on lands affected by Chernobyl in the 2000’s to consider remediation of lands. By planting rapeseeds with each step, the shoes seek to question how to heal the land damaged by the nuclear disaster through action.
For the soil sampling shoe, an opposite effect is desired, in which matter is collected rather than dispensed. Also instead of each step leading to soil collection, the action will have to be spaced out through out the duration of the walk, otherwise a lot of soil would be collected. Based on prior research on soil sampling, 40 mL of soil is suggested for a sample. This sample would then need to be located near the foot, whether directly in the shoe, or perhaps near the foot around the ankle.
E-Traces by designer Lesia Trubat documents the movement of dancers through sensors placed on the ballet shoe. This movement is then sent via wi-fi to a smart phone which then presents the traces performed by the dancer. This project seeks to create a digital artifact of the performance to function as a visual image to allow the dancer to study their movements in order to learn and improve from this tracking.
In considering the tracking function of E-Trace, this could provide an understanding for development of a tracking function for the soil sampling shoe. This would allow the shoe to determine when to collect soil, based on where on it’s position of a space, such as a park or trail.
Roller shoes are a type of footwear with an embedded wheel, allowing the wearer to glide across a surface when the weight is shifted onto the heel. Roger Adams, the founder of roller shoe company Heelys, patented this design in 1999 and has geared it towards the youth market ever since. Based on the company website, he “cut open a pair of sneakers, inserted a skateboard wheel, and Heelys were born!”. Current Heelys sneakers also feature a removable wheel which would allow the wearer to step without rolling. Although Heelys and other roller shoes are popular due to its recreational aspects by embedding a normal shoe with the potential for rollersport activity on any flat, hard surface, this has come not without controversy. From frustrated pedestrians and shopkeepers to concerned pediatricians, roller shoes is seen as a dangerously annoying and annoyingly dangerous footwear. However, even almost 17 years since this product come onto the market, several retailers still carry roller shoes in their inventory.
As a precedent work for the soil sampling shoe, roller shoes serve to be an interesting design for how technologies are embedded into the shoe, particular in the heel which makes direct contact to the ground. The pressure on the heel activates the wheel in the roller shoe, allowing the wearer to glide or roll across their surface. This insight provides consideration into how the wearer must interact with the soil sample shoe in order to facilitate the collection process. Although the shoe provides a more passive soil collection compared to existing methods, certain actions or gestures must still be performed in considering the interaction design aspects of the object. The soil extracted from the ground for the soil samples collected by the shoe needs to be accessible for analysis, thus can follow the retractibility of the wheel in the roller shoe.
In the first iteration of the soil sample shoe (working title is “Spore Stepper”), a circuit was built onto an existing shoe to allow soil sampling to occur. A circuit that controlled a servo motor was built that was controlled by a pressure sensor switch. A scoop and collection bag are built on top of the servo motor so that when the pressure sensing switch is closed, the servo motor would pick up dirt using the scoop attachment and deposit the dirt into the bag located directly behind the scoop. This circuit was then fastened to the a Vans Classic Slip on shoe by using zip ties to connect the breadboard where the microcontroller and some of the components are held to the flat part on top of the foot. The design of this shoe allowed for easy access to fasten the breadboard onto the surface. The switch was installed inside the shoe where the ball of the wearer’s foot would reside. This would allow the switch to be activated when pressure was placed at the front of the shoe, such as when the user is mid-step. The servo motor is then placed on the inner side of the shoe, adhered to the shoe using hot glue. The scoop attachment is angled downwards, so that soil would automatically get pushed into the scoop when the scoop is made. As the wearer steps, the servo motor is triggered, which dumps the dirt collected onto the scoop into a collection bag located at the other end.
This low-fidelity prototype is an early proof of concept to show a possibility of how a soil collecting device can be attached to a shoe. Although it is functional, several design and technical considerations can be made to refine this prototype. One major design consideration is how to fully integrate the components into the shoe rather than having the components sit on top of the shoe. This would entail building the electronics into the shoe in a more seamless manner. A technical consideration is to use another method of soil collection that would allow the soil to be collected more naturally with the step action of a user, rather than having a servo motor pick up the dirt. An addition of an inflation bulb such as the ones used for a turkey baster or blood pressure pump would allow for suction without digital components, though placing of this component in the shoe for proper inflation and deflation would be complicated without constant collection happening by the suction. Initial tests with a turkey baster also did not prove to be successful in collecting dirt.
One method to reconsider the soil collection methods is to use soft robotics to move the soil into a collection chamber inside the shoe. The soft robotics would take form of a pneumatic muscle located in the outsole of the shoe that can expand and contract to push the soil into a collection chamber also located in the outsole. The natural pressure from taking a step would push dirt into the entrance of the muscle through the tread. Only when the shoe is ready to collect dirt, through tracking the distance in between the last time of collection or at discretion of the wearer, the muscle will activate to “swallow” dirt into collection.
Although it would still need digital components such as a pump, microcontroller and power source, a soft actuator would be easier to implement into shoe rather than accounting for the full range of motion that is required by the servo motor. At this point in building the prototype, the actual artifact of the shoe was taken into consideration. As a speculative piece, it was important for the object of the shoe to present the potential functionality and conceptual elements of the piece, more so than to be a robust, efficient model (at least this is what I am telling myself).
To test out this method, I followed instructions set forth by the Soft Robotics Toolkit, an open resource for building soft robotics created by Harvard University and Trinity College Dublin, for building a fiber-reinforced actuator using a cardboard mold. A two part mold was constructed using cardboard pieces and then reinforced by hot glue to prevent leakage. EcoFlex, a silicon casting material by SmoothFlex, was then prepared according to specifications and poured into the mold. A piece of paper was placed in between the silicon on the top layer to act as a stiffener. This would constrain the actuator to bend in a specific manner rather when it is inflated.
After curing, the silicon pieces were pulled out and adhered to each other with additional silicon. Tubing was then inserted inside the actuator to the open chamber, which is then attached to an empty plastic bottle. The empty plastic bottle acted as a impromptu pump to inflate and deflate the silicon actuator.
By designing this silicon piece in a cylindrical shape with sections to inflate in succession, the actuator would be able to push dirt through a tube. This action would mimic swallowing, with the dirt being deposited in a “stomach”, or a storage area to be held until the walk is over and the collected dirt can be obtained for analysis. In considering how the cylindrical actuator will be designed, the work of F.J. Chen et al. for their work, “Soft Actuator Mimicking Human Esophageal Peristalsis for a Swallowing Robot” was referenced. This research developed a soft actuator that replicated a human esophagus to swallow by building a silicon body with horizontal chambers that would inflate in succession to mimic the muscles utilized in a human model. Although this design yields a model that is larger and more complex than what is needed for the soil sample shoe, it provides a basis for the possible functionality of implementing a soft actuator in the prototype.
In considering the final form of the overall shoe, designs from fashion footwear are referenced as examples to convey the concept and house the collection method in the shoe. DEGEN, a fashion company based in Brooklyn, New York created a line of outdoor inspired footwear in 2014 that incorporated elements of hiking boots in an unexpected manner. The result is a shoe that has a platform heels, with flashes of bright color at the heel, trim around the sole, and in the laces. The use of a fur trim and nylon cord gives the shoe an “outdoor” aesthetic, while the choice of color and chunky design of the treads read as more playful. The overall form sends a series of mixed messages due to this combination as a fashionable interpretation of a hiking shoe. The playful manner in which DEGEN approached designing the shoe results in an interesting object that can be utilized in considering the final form for the soil sampling shoe.
The “Jagger Platform Oxford” by design label, Jefferey Campbell presents another approach to footwear design that can be co-opted in the soil sample shoe. In this design, an oxford shoe has been extended at the outsole with a section created out of clear acrylic which creates a storage space for sequins. This seems to be a more humane version of the platform shoes of the 1970’s popular at discos in which clear heels could be filled with gold fish. Parts of the heel for these platform shoes would be removable to place, feed, or even replace the fish as a decorative item within the shoe .
By designing a portion of the soil sampling shoe to be clear and transparent, it would allow for the process for collecting the soil sample to be apparent, yet housed within the shoe. In following the designs for the 1970’s clear heeled shoes, parts of the heel could also be designed to be removable to retrieve the soil sample at the end of a walk.
One of the prototypes I am currently working on is the Hand-Substrate Interface. This was originally conceived to be part of the Data HarVest, but is now it’s own device. The concept for Hand-Substrate Interface is to create a wearable device that can be worn around the hand to capture information about the substrate surfaces, such as soil and wood. Rather than having to pull out probes to receive quantifiable data about the environment, the user would be able to implement gestures performed during a mycological foray, such as touching with the hand, to obtain this information.
The first iteration of this used a work glove as the base material for which sensors were placed onto. One of these sensors included a soil moisture sensor that is deconstructed so that it can fit on the glove. A soil moisture sensor typically consists of two probes that function as a variable resistor. These probes are placed into the ground to measure the conductivity between the two points. The more moisture or water that is in the earth, the higher the conductivity will be between the probes, resulting in lower resistance.
The sensor is built into a glove by embedding conductive materials so that index and middle fingers of the gloves becomes the probe. When the two fingers are inserted perpendicularly into the ground, a reading can be taken of the current moisture levels. As a wearable, the sensor becomes a more portable and readily accessible to be used, while the gesture required for taking a reading allows the user to interact with the physical environment in an intimate manner. Since only two fingers of the gloves are currently being utilized for the soil moisture sensor, there is potential to add additional sensing capabilities to the other fingers.
Although the glove provides a structure for the components and sensors to be mounted onto, the glove is also a barrier for the fingers’ direct interaction with the environment. In building these prototypes, one goal is to build wearable devices with embedded environmental sensors which this prototype addresses. However, another goal is to facilitate a more aware interaction with the natural environment and the use of the glove would mask this action. This would mean not only collecting qualitative data from using the probe, but also allowing for a qualitative experience, such as allowing the user to also feel how wet the substrate might be, in addition to obtaining a reading.
The Hand-Substrate Interface is currently being reiterated in two different ways. One is revisiting the concept of the glove, but utilizing different materials to allow for a more tangible interaction. The materials include stretchable fabrics such as knits so that the glove can sit closer onto the user’s hand, along with textiles with a more open structure such as mesh and netting so that direct contact can be made with the substrate, while providing a surface for the circuits can be embedded into. The design for the glove iteration takes inspiration from fashion designer Rachel Freire’s work in e-textiles. In working with performers and musicians to build wearable devices that augment their performance, Freire has developed a process to more seamlessly embed the technologies into garments that are worn close to the body, such as gloves. One of these projects, Mi.mu, is a collaboration between technologists, designers and musicians to build a glove that can control a musical interface with gestures. Through several iterations and tests, they have created a functional device that an artist is able to use, without hinderance to their movement.
Another iteration of the Hand-Substrate Interface is to use conductive temporary tattoos as a method to rethink the relationship between how technology resides on the body to interact with environment. By installing the probes directly onto the body by adhering the traces to the skin via temporary tattoos, there will be little to no barrier between the hand and the environment. A wrist band will be constructed to house the electronic components such as the microcontroller and interface to work with the sensor. The wrist band will be connected to the conductive tattoo with contact points located on the inside of the band that will be worn against the skin.
The conductive temporary tattoo method was first tested based on the work in DuoSkin by Cindy Kao, et al. In their paper, the group documents a process of creating temporary tattoos using gold leaf adhered to temporary tattoo paper and then applied onto the surface of the skin. This method would create skin-friendly circuits that are worn on the body that can also provide a basis for surface mounted LEDs.
The materials for this process utilizes gold leaf, gold leaf adhesive, and blank temporary tattoo paper which consists of one sheet of silicon material on a paper backing that acts as a base and an adhesive sheet. To test out this process, I made a rectangular piece (approximately 4″ x 11″) of the temporary tattoo with gold leaf to test how it will apply to the skin, rather than using a stencil. I first coated a section of the glossy side of the paper-backed sheet with gold leaf adhesive and allowed it to cure for 30 minutes. Afterwards, I applied a layer of gold leaf onto the surface and trimmed the paper down. The adhesive sheet was then applied so that the whole gold leaf area was covered with a clear plastic sheet.
To use as a tattoo, I cut out smaller rectangles of the tattoo out using scissors. However, when peeling off the clear plastic sheet to expose the adhesive layer, some of the gold leaf layer was pulled off the silicon layer. In the DuoSkin layer, the authors did discuss applying multiple layers, perhaps to guard against this happening. This could also be a result uneven application of the gold leaf adhesive as well.
To test if a piece could resist the plastic area being peeled off, a larger rectangular piece was cut off with moderate success. The sticky exposed side was then placed downwards on the skin and a wet towel was applied against the paper, thoroughly wetting the tattoo for about 15 seconds. The paper then slid off and the tattoo was applied to my forearm. Although the result is not totally pristine it does validate the procedure put forth the DuoSkin group.
By utilizing materials for creating temporary tattoos, this process ensures a skin-friendly method of building circuits onto the body. However, the insulation that the adhesion and silicon used in the temporary tattoo process does create a hinderance in thinking about the overall design of the probe. Using a multimeter, it was hard to get a stable read on the silicon surface of the tattoo. By peeling up a bit of the tattoo to get a reading on the adhesion layer, there was continuity with fairly low resistance (approximately 5 ohms across). However, since this is the layer that is supposed to sit against the skin, it is difficult to access the layer without ripping the surface of the tattoo. The ability to have exposed traces is important in considering building the tattoo into a soil moisture sensor. The two traces that create the probe need to be able to make contact with the earth in order to obtain a proper reading.
In researching other methods for safely applying gold leaf to the skin, I came across makeup tutorials for applying gold leaf as a highlight to the face, body and even hair. In Fall 2011 and again in Winter 2014, there were brief trends in which gold leaf accents was popular enough to warrant many online tutorials to guide people who were curious about incorporating this trend into their look.
Based on the “How to Make Your Holiday Makeup Look Super Fancy” tutorial put forth by fashion blog, Refinery 29, gold leaf can be applied directly to the body using “eyelash glue, Vaseline, coconut oil, and jojoba oil”, although gold leaf should be able to adhere somewhat to the skin without an adhesive. In Honestly WTF’s “DIY Gold Leaf Faux Jewelry”, the author suggests using spirit gum, a solution usually used in costuming to adhere a range of false hairs and prosthetics directly to an actor’s skin. Because only one layer of adhesion is applied to adhere the gold leaf to the skin surface rather than the insulating silicon top piece for the temporary tattoo, the gold leaf would have exposed traces that would allow for reading the soil moisture through sensing changes in resistance.
TO BE CONTINUED as a I acquire eyelash glue // other skin safe adhesives!
Along with materials and objects, I have also been thinking about the various gestures that are associated with mushroom hunting. In doing so, it has allowed me to think about what to produce in a more abstract way. In thinking about gestures, I also included sensorial inputs that are specific to mushroom hunting, such as hearing sounds of other animals, other humans, and the environment (rain, wind, leaves).
A wide array of literature exists within interaction design regarding gestures to provide input. Gestures to control and manipulate systems provide even more intimate relationship between the human and computer in which buttons, switches and dials are replaced with an array of actions. This has been made possible through the use of capacitive sensing, wearable computing, computer vision, infrared sensing and other technologies. If the gesture associated with some form of control in a system comes so naturally to the user, input can be made with little to no effort by the user. This could be unfortunate part of the design if it is unintentional. Thus distinct gestures through body positioning, specific finger movements, tapping rhythms, etc have been researched and employed to create frameworks and vocabularies of gestures for interacting with a system. However, passive input, input that occurs without the user noticing or actively controlling, has interesting potential to augment the normal actions and gestures. In particular, in mushroom hunting, many associated gestures are geared towards recognizing and identification of fungi. By embedding technologies in these gestures, we can enhance the user’s capabilities during a walk.
In the first round of prototypes I ideated on storage systems for foraged items during a mushroom foray. These are more obvious to the traditions of mushroom hunting where you are collecting large and small fungi samples as you move throughout the forest. These are alternatives to the traditional use of a basket or bag and were created with functionality and wearability. Building on these alternative collection systems, I am working on other ways to gain an understanding of the fungi in the ecosystem beyond the harvesting of mushrooms.
In talking to mycologists and reading literature on fungi, there is actually a large amount of fungi in the form of mycelium, spores and hyphae, rather than the fruiting body, the mushroom. Soil sampling is suggested as a way to gain a picture of the fungi that is the in the environment, regardless of the mushroom, with estimates of 10^6 spores per gram of soil, with several species present.
The methods of isolating and identifying these species include soil dilution and plating, in which the sample is placed on agar to germinate spores and hyphal extraction in which larger bits of hyphae are extracted from the sample and placed in agar. The plating method was created by mycologist, John Henry Warcup, who was able to demonstrate that fungi could be isolated by placing a soil sample directly on an agar plate, allowing hyphal tips to grow from the soil. Fungi that is endophytic (growing in) or epiphytic (growing on) on a substrate can also be extracted, isolated and identified after collection. For example, to extract epiphytes, a leaf that contains potential fungi can be washed, with the water that is rinsed off the leaf raised in agar to check for spore germination. To access the endophytic fungi, the exterior of the leaf is first sterilized to remove any bacteria, and then ground using mortar and pestle or cut up to expose the interior. This can then be mixed with water to be plated onto agar. These processes are done later on in a sterile lab environment to prevent cross contaminations. Rather than thinking about this process of extraction and identification, I am more interested in rethinking about this soil sample collection process which is done while you are out in the environment.
Based on a soil sampling report put forth by the EPA to assess VOC (volatile organic compounds) in soils, four main factors play into an effective soil samples which include effervescence, sample size, holding times and percent solids. Effervescence is the formation of bubbles when the sample comes into contact with an acidic preservative. If the bubbling occurs, the sample needs to remain unpreserved since it could become deleterious to the soil. Sample size ranges, but is suggested to be at 40 mL. Holding time is the length of time to hold an unpreserved sample before it is tested, which the document advises a 48 hour period where the sample can sit on ice before entering the lab for testing. Percent solids is the total amount of solid material within a sample, this is to make sure that the sample has enough material to be analyzed back in the lab. Although these procedures and factors may be more relevant to analyzing VOC content, this could provide guidelines for soil sampling for fungi.
In guides for soil sampling specific to mycology, the process is changed slightly in order to preserve the fungi content. One of these guides is the Handbook for Mycological Methods put out by the Food and Agricultural Organization of the United Nations for study of the impact on mycology on coffee production. The handbook provides specifications for collecting fungi from a tree, air, and soil.
Collecting endophytic fungi from a tree:
“Cut three shoots from different parts of each tree sampled on the proximal side (side closest to the main stem) of the second node from the apical meristem (the growing point) of each shoot. At the lab, re-cut the stem to a length of about 2 to 3 cm starting from the proximal end of the second internode (the smooth stem between nodes). Surface sterilize the segments in a strong solution of hypochlorite (5% available chlorine) for 5 min. Shake several times. Decant the sterilent after the appointed time and replace twice with sterile water. After decanting the rinse water, blot on sterile filter paper in a sterile petri dish. Using 70% alcohol and a flame to sterilize your instruments, re-cut about half of a cm from each end of the segments with a scalpel in another sterile petri dish containing sterile filter paper while holding it with some strong forceps to yield segments 1 to 2cm in length. Gently push up to five segments in a radiate pattern into a plate of D/2G18 and incubate. “
Air sampling, as the FAO handbook suggests, is taken with exposed agar plates in order to determine settling of the spore load while the coffee bean is drying or sitting in a facility. This technique they have adopted is chosen based on the type of fungi they are studying – those that affect the coffee production process. As a result, this technique will most likely capture comparisons of fungi in different environments to yield a quantitative comparison rather than a qualitative one.
With soil sampling, the handbook notes what information can be attained through this process.
“Although commonly employed, taking a single ‘grab sample’ of soil is not a very useful activity. Any two samples whether separated by a meter or a kilometer will be different because they cannot be the same. What is of interest is not the fact of the difference but ascribing the difference to some feature of ecological significance.
As such the soil sample is as follows:
Use a strong spatula to remove about 20g of soil into a sterile bottle of an appropriate size after brushing away loose material and the uppermost layer of soil (usually 1 to 3 cm) until the small fibrous roots are exposed. Sample the soil around these roots. Away from the coffee stem sample at the same depth as the ‘0’ sample. To sample in the orchard, the first sample, labeled ‘0’, is taken within 10 cm of the main stem of a coffee plant, the second, labeled ‘1’, is taken below the edge of the foliage of the same plant and the third, labeled ‘2’, is taken along the line defined by the first two but at a point such that it is as far as possible away from any coffee plant but still within the plantation system. A fourth sample (label ‘3’) may be taken near to but outside of the plantation for reference.
In this process, four samples are taken for analysis at different points from the coffee plant, one near the root, one near the foliage, one within the plantation, and one outside of the plantation. This analysis would thus provide a perspective on the impact of fungi on the coffee plant itself in relation to distance away from the tree.
In the soil sampling section, it is also recommended that the samples be air dried if not immediately analyzed. This would allow for proper storage before the dilution process to isolate and identify fungi within the sample.
Other things that are used for sampling include surfaces such as cement and brick in which a swabbing technique is utilized to collect a sample.
Other techniques that are included in this guide are for surfaces such as cement and brick in which a swabbing technique is utilized and for insects. The guide recommends that insects be captured live and placed in a petri dish containing a enumeration media (like agar). Any fungi in the fecal matter and footprints that the insect leave behind could then germinate in the dish. The insect can then be crushed and diluted to test for mycological content
In Progress of Mycology, most soil fungi are between the top 10 -30 cm of soil, after litter and humus is cleared from the top. In this book, the sample is supposed to be representative of a site, thus “composite samples are obtained by mixing equal amounts of material taken from soil samples collected over a wide area”. One technique also uses Scotch tape to take successive samples from a soil surface.
The Handbook of Industrial Mycology provides another source for sampling fungi for mycology, called baiting, in which substrata can be collected from the space to provide a habitat for the fungi or placed in a container that has specific environmental conditions to encourage growth (moist chambers). Fallen and dead wood can also be collected for further analysis, especially if decay is present. These small stem samples are them split and placed in a media before incubating to germinate fungi.
Although there are a lot of variations of how to collect and process the soil samples, it is still an important technique to be used to study fungi presence out in the field, especially for those that might exist without mushrooms. In these soil sampling methods, the collector is usually required to dig and scoop a sample of the soil into a collection chamber. This routine is repeated several times and in several locations depending on the nature of the study. Since my project is focused on citizen science, the goal is to just provide an overall species list of fungi that is present in an area during a foray in order to count frequency. This could mean that a soil sample is collected at designated points at intervals (for example, collect a sample every 100 meters) or whenever the participant finds a mushroom, they can take a sample. Although the latter is less methodological and might be less precise, when working with citizen science, there is a balance to maintain between lowering barriers to entry and creating a rigorous procedure. This was stated during an interview with one of the club mycologists regarding their process with DNA sequencing and changing the process to accommodate various fidelities during testing. *find dat quote* There might also be a preference to collection methods such that instead of keeping separate containers to prevent cross contamination of samples (FAO coffee production and fungi), it may be easier and beneficial to create one larger sample using multiple smaller samples collected throughout a designated area.
This has lead to work on some initial designs for a soil sampling shoe based on other work during the ideation process. This concept was initially inspired by soil and dirt becoming trapped in the treads of the shoes during a hike – can shoes be designed with intentional dirt trapping to collect soil samples? This passive collection would utilize a gesture (stepping) with wearable technology worn on the foot.
Shoe tube: soil sample is collected through a tube
Multiple tubes: multiple samples can be collected through stepping
Pt. 3 of Forage Storage prototypes is the Sleeve Storage. This design adds in additional panels on a sleeve so that your arms can store additional items. The idea comes from thinking about where added storage can be added to clothing that normally doesn’t have storage and designing it so that it doesn’t interfere with the movement of that area.
For this prototype I first made a single sleeve out of a yellow canvas fabric. The pattern is based off of tracing an existing long sleeve shirt and the edges were completed using a serger to prevent any fraying. I chose to do this over building on top of an existing jacket or making a whole jacket from scratch so I can just focus on working with just the sleeve.
With the sleeve model, I first used kraft paper to model where the panels can fold over and expand. Using the measurements that I got from the paper models, I used ripstop nylon make the panels and window screen material for the pockets. They are held in place with velcro and held to the sleeve using safety pins.
I went with two different designs for the panels, one for the upper arm and one for the lower arm. The lower arm design is attached to the sleeve at the bottom and wraps around the arm. The upper arm design is attached to the sleeve from the top to middle portion so that the panel folds open and only occupies about half of the arm. The lower arm design could potentially store more items, though it is a little tricky to reach around the forearm to release it.
In building these prototypes for forage storage I have tested working with various materials and concepts for collection of physical artifacts for mushroom hunting. These designs can definitely be applied for other fields and uses, but is primarily designed to allow a person to more effectively collect fungi.
This post contains prototypes for the Front Pack storage prototype. In the process of making these items, it was interesting to think about the resolution of these prototypes. For example, the sleeve storage (featured in part 3), which could potentially be incorporated into a jacket, is actually just the sleeve because it’s easier to just sew the segment of the clothing, rather making a full blown jacket. But at the same time, making the sleeve gave me more control over the structure and material than using an existing sleeve. In thinking about craft and making, there is a usually a fine balance I try to maintain between having the object refined enough to speak for itself conceptually, but also be straightforward in terms of materiality and maintain the presence of the hand. I am sure I will have to unpack that statement more at some point in my life, but not now!
Here is the sketch for the Front Sack. The design allows your to easily store your foraged goods into the front of your body rather than having to reach around to a backpack or have to carry something like a basket or bag in your hands. The Front Sack is made out of two pieces of neoprene sewn together with a netting pouch that enclosed with a zipper. The neoprene pieces also form a smaller slotted pocket at the top of the sack that can be used to store wax bags that are used in forays to separate your collection within a basket or bag. The neoprene part of the bag also has grommets at the top edges so that it can clipped onto a harness via carabiners. This allows you to just pull the front sack on and off as needed at the beginning or end of a foray. The harness itself is actually from my Portable Workspace project back in the summer – it was helpful to have a base to work on in terms of figuring out the initial measurements of the project.
More sketches of the bag to figure out dimensions and how the layers go together.
Since I wanted the bottom of the mesh bag to be larger than the top, I created a deeper box bottom for the lower half so that when the sides of the squares were sewn together, it would have a larger inset.
Here is the pattern I made for the neoprene pieces. I usually write notes on the patterns to make the cutting and sewing the pieces out more smoothly. It’s like the textiles version of carpentry’s motto “Measure twice, cut once”. Well actually it’s the same thing. This is definitely a more rational form of making than just experimenting with materials. Though when making something with the intent that it needs to be worn on the body, it is usually best to measure out a lil bit before you put something together!
As you can see, the Front Pack can actually store quite a bit of goods. In this case it was nylon fabric that I used for another prototype. But it is workable and potentially functional so that is always good.