You guys have to check out what Larry Cheng and his team at Penn State did because it actually fixes one of the biggest problems in wearable sensors! So e-tattoos — these thin polymer sensors applied like temporary tattoos — are great but they fail on hair or when you move much, because standard electrodes sit ON the skin with an air gap that degrades your readings. Hydrogels were a partial fix but they break down too fast under prolonged use. Cheng's team developed this WE-PPD conductive ink instead, which is a water-based ethanol/polyvinyl alcohol solution mixed with PEDOT:PSS for conductivity and DBSA as the plasticizer to make it stretchable. Because the ink flows directly into skin contours rather than sitting on top of them there is no air gap so signal quality is massively higher during exercise or daily activity!
And this is where it gets genuinely cool — they added food dye so you can customize the electrode's design and color however you want, painting fox shapes, cartoon characters, even Superman logos onto people. The ink itself starts transparent but becomes whatever pigment you choose while remaining flexible enough to stretch up to 170 percent before failing. They tested it on actual human subjects running a treadmill, lifting weights, doing gesture control for robotic prosthetics, and even measured brain activity through hair without any irritation over at least 12 hours of continuous wear! The whole idea is that the expensive electronics can be separate while these electrodes are disposable — one bottle could paint dozens of sensors over several days. They already filed a provisional patent on it and honestly I bet this becomes standard in medical clinics before long!
Source: https://arstechnica.com/science/2026/07/these-painted-e-tattoos-could-be-the-future-of-wearable-biosensors/
And this is where it gets genuinely cool — they added food dye so you can customize the electrode's design and color however you want, painting fox shapes, cartoon characters, even Superman logos onto people. The ink itself starts transparent but becomes whatever pigment you choose while remaining flexible enough to stretch up to 170 percent before failing. They tested it on actual human subjects running a treadmill, lifting weights, doing gesture control for robotic prosthetics, and even measured brain activity through hair without any irritation over at least 12 hours of continuous wear! The whole idea is that the expensive electronics can be separate while these electrodes are disposable — one bottle could paint dozens of sensors over several days. They already filed a provisional patent on it and honestly I bet this becomes standard in medical clinics before long!
Source: https://arstechnica.com/science/2026/07/these-painted-e-tattoos-could-be-the-future-of-wearable-biosensors/