Page 96 - TEXtalks September/October 2021

96
Textile-based

battery powered

by Human Sweat

Scientists from the Nanyang Technological
University, Singapore (NTU Singapore) have
developed a soft and stretchable battery
attached to an absorbent textile substrate
powered by human perspiration. The
Washable smart clothes flake electrodes that generate electricity in
prototype battery consists of printed silver
the presence of sweat. Measuring 2 cm by 2
cm and as flat as a small paper bandage,
powered by Wi-Fi the battery is affixed to a flexible and sweat
absorbent textile that is stretchable and
attachable to wearable devices, like watch-
es, wrist bands, or arm straps, NTU Singa-
pore said in a press release.

Researchers at Purdue University have developed washable smart clothes which Wi-Fi has powered. A flexible The scientists tested their device with
silk-based coil has been sewn onto a smart textile and can harvest energy from radio and Wi-Fi signals in the artificial human sweat to demonstrate its
environment. Purdue University engineers have developed a method to transform existing cloth items into potential use when incorporated in wearable
battery-free wearables resistant to laundry. The developed smart clothes have been spray-coating with highly biosensors and other electronic devices.
hydrophobic molecules, making them render repellent to water, oil, and mud. Researchers have reported that an individu-
al wearing the battery around their wrist and
These smart clothes are almost impossible to stain and can be used underwater and washed in conventional cycling on a stationary bicycle for 30
washing machines without damaging the electronic components sewn on their surface. minutes was able to generate a voltage of
4.2 V and output power of 3.9 mW that was
Unlike everyday wearables, the Purdue smart clothes do not require batteries for powering. The clothes can sufficient to power a commercial tempera-
power the circuitry sewn on the textile by simply harvesting energy from Wi-Fi or radio waves in the environ- ture sensor device and send the data
ment. One example is a battery-free glove that illuminates its fingertips every time the user is near a live cable continuously to a smartphone via Bluetooth.
to warn about the possibility of an electric shock. Another is a miniaturized cardiac monitoring system sewn on
a washable sweatband capable of monitoring the wearer's health status. The technology can be fabricated in The battery could help reduce harmful
conventional, large-scale sewing facilities, which are expected to accelerate the development and commerciali- electronic waste, as it does not contain
zation of future smart clothes. heavy metals or toxic chemicals. The
scientists behind it believe it could lead to
innovation within the wearable tech industry.

September/October 2021