Light-Up ‘Skin-Like’ Plastic Is the Next Step for Wearables
March 30, 2022 – Imagine a tiny, stretchable, glowing patch on your finger or arm, and you’re unveiling the latest advances in wearable technology from researchers at Stanford University.
Engineering professors have created a new polymer or synthetic plastic that can glow. They used it to make a flexible color display similar to what you see on any digital screen. But unlike your cell phone, it can withstand being stretched or bent.
The latest discovery in the quest to create “skin-like” wearable electronics – thin, flexible devices that promise greater comfort and precision than the more rigid and bulky wearables of today.
Unlike previous attempts at flexible displays, this model does not lose brightness when stretched. You can attach it to your hand or finger, and it won’t tear when bent or bent.
Engineers say this vibrant stretchy technology could one day open up many new ways to improve health and fitness.
For example, instead of wearing a clunky fitness tracker on your wrist, imagine wearing a skin patch that constantly monitors health data like heart rate with a display right on the device.
Even more futuristic: imagine a telemedicine session where a doctor can see and hear you and examine your skin texture for problems with a flexible patch.
“Getting closer to the human body will allow us to get more information,” says the chemical engineer. Jean Bao, Ph.D., was one of the Stanford researchers who developed the new material. Skin-like wearable devices are one way to approach all kinds of measurements.
What can we learn from having light next to the skin?
Flip any fitness watch that can track heart rate, and you’ll see flashing green lights on the bottom of the eye.
These LEDs emit light through the skin, then reflect into the watch. The watch then uses the wavelength of that reflected light to measure things like your heart rate or blood oxygen levels.
For accurate readings, the brighter the light, the better. Researchers have long been trying to create an LED that is softer and more flexible than current technology, but they ran into three main problems:
- Making a material flexible enough to stretch without breaking
- Generating light bright sufficient for accurate readings
- Reaching voltage levels with less risk to power the light (electrocution from wearables is not ideal).
This new Stanford Study is already three years in work. Bao and her research team detail how they overcame these hurdles and developed a flexible film that emits bright light at low voltage. She says this material can generate light at least twice as bright as a typical mobile phone display.
Potential future healthcare applications
As future versions of this luminous material become more flexible and durable, devices made from it will be able to measure things that wearable devices can’t today, Bao said. For example, the sound of a person breathing or the level of cortisol, the stress hormone, can provide context for common measurements such as changes in heart rate and help people understand what they mean.
“The addition of cortisol makes [a reading] more accurately determine whether we are seeing is true stress or just some sort of fluctuating heart rate,” says Bao.
Bao says that skin-like displays and sensors could also change the way we use electronics. For example, in telemedicine, a person can stick a wearable film on the area of the body that needs to be examined. The wearable device can then generate a 3D interface, allowing the doctor to view the site from afar.
Meanwhile, more research is already underway. Bao predicts that medical and commercial use will be possible in 5 years.
“The future of this elastic technology will lead to advances in telemedicine as it can offer a real-time display of information,” says Bao. “If we can make them look like skin, then the possibilities are limited by one’s imagination. And that’s what we’re aiming for.”