Soft and stretchable power pack has tiny lithium-ion batteries

Normally when we talk about power packs or batteries for electronic devices we are looking at large rigid structures that take up lots of space inside the device. That sort of battery works just fine for gadgets like phones or laptop computers, but when you are talking about thin wearable sensors and other electronics meant to be actually on the skin powering the devices is a challenge.

Researchers at the University of Illinois including John Rogers are working on a new type of power supply and this one is thin and flexible. It achieves that thin and flexible nature by taking the large lithium ion battery and chopping it into multiple tiny squares that are connected with stretchable circuits. This combination of tiny batteries and stretchable circuits makes for a battery that can stretch and bend.

Rogers and fellow researchers have created a new evolution of their flexible battery using millimeter-scale solid state lithium-ion batteries that are connected using stretchable circuits to solar cells and deposited on a flexible substrate in a single layer. The construct is then folded so that the solar cells sit on top of the batteries in the final device. The demonstration of the tech integrates the battery and solar cell into a device with a thermal sensor and NFC tech to track and log body temperature.

The thin device is able to stretch up to 30% without affecting its solar power generating capabilities and was tested on people while biking and bathing with success. The thin nature of the sensor means that the wearer barely knows it is there. This sort of sensor could have potential use in the medical field to transmit data about patients in a hospital wirelessly, freeing up staff to focus on things other than constantly monitoring vital signs for those who are severely ill.

SOURCE: Spectrum