Credit: Wei Gao
Photo of Biofuel Cell Powered E-Skin
One of the ways we experience the world around us is through our skin. From sensing temperature and pressure to pleasure or pain, the many nerve endings in our skin tell us a great deal.
Our skin can also tell the outside world a great deal about us as well. Moms press their hands against our foreheads to see if we have a fever. A date might see a blush rising on our cheeks during an intimate conversation. People at the gym might infer you are having a good workout from the beads of sweat on you.
But Caltech’s Wei Gao, assistant professor in the Andrew and Peggy Cherng department of Medical Engineering at CalTech wants to learn even more about you from your skin, and to that end, he has developed an electronic skin, or e-skin, that is applied directly on top of your real skin. The e-skin, made from soft, flexible rubber, can be embedded with sensors that monitor information like heart rate, body temperature, levels of blood sugar and metabolic byproducts that are indicators of health, and even the nerve signals that control our muscles. It does so without the need for a battery, as it runs solely on biofuel cells powered by one of the body’s own waste products.
“One of the major challenges with these kinds of wearable devices is on the power side,” says Gao. “Many people are using batteries, but that’s not very sustainable. Some people have tried using solar cells or harvesting the power of human motion, but we wanted to know, ‘Can we get sufficient energy from sweat to power the wearables?’ and the answer is yes.”
Gao explains that human sweat contains very high levels of the chemical lactate, a compound generated as a by-product of normal metabolic processes, especially by muscles during exercise. The fuel cells built into the e-skin absorb that lactate and combine it with oxygen from the atmosphere, generating water and pyruvate, another by-product of metabolism. As they operate, the biofuel cells generate enough electricity to power sensors and a Bluetooth device similar to the one that connects your phone to your car stereo, allowing the e-skin to transmit readings from its sensors wirelessly.
“While near-field communication is a common approach for many battery-free e-skin systems, it could be only used for power transfer and data readout over a very short distance,” Gao says. “Bluetooth communication consumes higher power but is a more attractive approach with extended connectivity for practical medical and robotic applications.”
Devising a power source that could run on sweat was not the only challenge in creating the e-skin, Gao says; it also needed to last a long time with high power intensity with minimal degradation. The biofuel cells are made from carbon nanotubes impregnated with a platinum/cobalt catalyst and composite mesh holding an enzyme that breaks down lactate. They can generate continuous, stable power output (as high as several milliwatts per square centimeter) over multiple days in human sweat.
Gao says the plan is to develop a variety of sensors that can be embedded in the e-skin so it can be used for multiple purposes.
“We want this system to be a platform,” he says. “In addition to being a wearable biosensor, this can be a human–machine interface. The vital signs and molecular information collected using this platform could be used to design and optimize next-generation prosthetics. ”
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
- South Korean scientists have developed new 'e-tattoos' that can monitor health conditions
Its developers say the tech is still in its early stages, but one day it can offer a non-intrusive and personalised way to monitor health conditions. View on euronews ...
- South Korea develops electronic tattoo that can alert patients to possible health problems
South Korean researchers at the Korea Advanced Institute of Science and Technology have created an electronic tattoo that will be able to track patients' health.
- Electronic tattoos could help monitor your health
STORY: South Korean researchers want to use wearable ink to monitor your vital signsLOCATOR: Daejeon, South Korea[Steve Park, Materials Science and Engineering Professor / Korea Advanced Institute of ...
- 'Electronic tattoo ink' developed by South Korean researchers to monitor health
South Koreans may soon be able to carry a device inside their own bodies in the form of a bespoke tattoo that automatically alerts them to potential health problems, if a science team's project bears ...
- Teleconsultation to prevent skin conditions in infants
A recent publication in JMIR Pediatrics and Parenting reported that mothers of infants are prone to experiencing parenting stress, which adversely affects mothers' and children's well-being.
Go deeper with Google Headlines on:
Go deeper with Bing News on:
Electronic skin human-machine interface
- What Should a Nine-Thousand-Pound Electric Vehicle Sound Like?
E.V.s are virtually silent, so acoustic designers are creating alerts for them. A symphony—or a cacophony—of car noise could be coming to city streets.
- Brain-Computer Interfaces: Separating Fact From Fiction On Musk’s Brain Implant Claims
Since our electronic devices are not ... even close to the type of brain-computer interface we see in science fiction. Our understanding of the human brain is unfortunately rather limited.
- Wearable Plasmonic Biofluid Sensor For Personalized Medicine
c Actual image of an as-prepared microfluidic SERS sensor attached to the skin. d System-level block diagram showing ... a compact and tailored Raman analyzer with a comfortable human-machine ...
- Hydrogels with Flexible Electronics Herald New Medical Possibilities
Scientists around the world are actively using hydrogels as novel materials to interface with the body ... intelligent human-machine interfaces, medical engineering, and next-generation electrical ...
- Mastermind behind human touch robot skin awarded The Princess Royal Silver Medal
A young engineer whose County Durham company is pioneering technology that gives robots human-like touch sense has been handed a prestigious award for innovators. Dr Atif Syed, who founded ...