s k i n . el e c t r o n i c s

Skin Electronics represents a cutting-edge domain where art, science, and technology converge, enabling the human body to interact with the digital world in unprecedented ways. It explores the integration of wearable sensors, conductive materials, and flexible circuits directly on or near the skin to create systems that respond to environmental stimuli or body signals. This fusion of functionality and aesthetics unlocks new dimensions for creative expression, medical innovation, and human-computer interaction, challenging the boundaries between the organic and the synthetic.

This week in the Fabricademy, we delve into the realm of Skin Electronics, seeking inspiration from visionary projects and pioneers at the intersection of art and science.

i n s p i r a t i o n

ELECTRONIC TATTOOS BY JOHN A. ROGERS

John A. Rogers revolutionized wearable technology with his development of "Electronic Tattoos." These ultra-thin, flexible circuits adhere seamlessly to the skin, enabling real-time monitoring of physiological data like heart rate, hydration levels, and muscle activity. His work transforms wearable electronics into something unobtrusive and almost imperceptible, paving the way for next-generation medical diagnostics and human-machine interfaces. Rogers’ approach emphasizes functionality and precision, inspiring a pragmatic yet innovative perspective on Skin Electronics.

g l o v e . p r o t o t y p e

Trying to make my first glove, I started by following the instructions from the first video I found on YouTube about glove-making.

I traced my hand on paper to create a basic pattern, keeping it simple for a quick test. Since this was just a prototype, I decided to make a three-finger glove using a two-axis stretch, skin-colored Lycra. After finalizing the pattern, I carefully transferred it onto the fabric, ensuring the stretch direction would allow flexibility and comfort.

Once the fabric pieces were cut, I stitched them together, testing the fit and movement. The Lycra’s stretch worked well, but I noticed some areas where the seams needed adjustments for better finger mobility. The tutorial helped guide me through the process, but I quickly realized that small tweaks were necessary to get the right fit. This quick prototype gave me a good understanding of how the material behaves and how I could improve the pattern before attempting a full glove.

The next step was integrating a DIY flex sensor into the glove. My plan was to attach the sensor along the fingers to capture movement and translate it into data.

f l e x . s e n s o r

To create the DIY flex sensor, I used conductive thread, tape, and a piece of velostat, guided by this youtube video.

Velostat is a pressure-sensitive material that changes resistance when bent, making it perfect for detecting movement. I started by cutting a thin strip of velostat, ensuring it was long enough to fit along the finger section of my glove. Then, I placed two parallel lines of conductive thread on either side of the velostat, securing them with tape to keep everything in place.

The key was to ensure that the threads didn’t touch each other directly, as the velostat needed to act as a variable resistor between them. When the sensor was straight, the resistance remained high, but as it bent, the resistance decreased, creating a measurable change.

After assembling the sensor, I tested it in the Arduino IDE using an ESP32-C3 Super Mini. I connected the conductive thread ends to one of the analog input pins with pull-down resistor and ground, then ran a simple analog read code to measure resistance changes. The sensor responded when I bent it, but the results were not too satisfying—the range of data variation was quite small, making it difficult to get precise readings.

To enhance performance, I considered layering multiple sheets of velostat or using a different conductive material with better sensitivity.

In the next step, I replaced the conductive thread with conductive textile, hoping to get a more stable and responsive sensor. I cut two thin strips of conductive fabric and placed them on either side of the velostat, ensuring they remained parallel and didn’t touch. I then secured everything with tape, making sure the layers stayed firmly in place while still allowing flexibility. This setup provided a larger conductive surface, which I suspected would improve the sensor’s sensitivity.

After assembling the new version, I tested it again with the ESP32-C3 Super Mini in the Arduino IDE. The difference was immediately noticeable—the range of data variation was much wider, making it easier to detect bending movements. The conductive textile provided a more consistent connection compared to the thread, reducing fluctuations and improving overall accuracy.

After making the flex sensor, I sewed it onto the glove, attaching it to one finger. Initially, I tried sewing through the tape that held the sensor layers together, but the needle couldn’t pass through it properly. To work around this, I decided to sew the conductive fabric directly onto the glove using conductive thread, ensuring a strong electrical connection. Once that was in place, I used regular thread to sew the velostat and the second layer of conductive fabric, securing the entire sensor to the glove.

However, after reconnecting it to the board, I noticed a drop in functionality. The sensor’s response became weaker, and the range of data variation was even smaller than before.

I suspected that the stitching process had altered the sensor’s pressure distribution or caused unwanted resistance in the conductive fabric. The layers might not have been making proper contact, or the conductive thread could have introduced inconsistencies in the electrical pathway.

To fix this, I started looking for a fabric tape that could securely hold all the parts together without interfering with flexibility or conductivity. A softer, non-rigid adhesive could help maintain good contact between the layers while avoiding the issues caused by sewing. This experiment highlighted how delicate the balance is between structure and functionality in wearable electronics, pushing me to refine my approach for the next version of the glove.