Powering of electronic wearables

The market for electronic wearables is booming, not least in the medical field with the increase in digital health ap-plications, with more and more people able to monitor their health from home.
Smart wearable patches require unobtrusive and small sources of power to operate, which also need to be flexible, and this can be a challenge. The technology for flexible batteries is, however, improving fast, having evolved in line with the growth of the wearables market from 2014 onwards. 
Amongst the achievements in this technology are Li-polymer (LiPo) batteries which allow for flexible designs that can be molded to small wearables.
One promising application under development is apparently smart labels using thin film batteries, which e.g. can help to monitor the temperature of goods during shipment or storage. Developments planned for the consumer wearable market involve flexible ceramic and polymer or swollen gel-polymer electrolytes. 
Wearable devices and a part of flexible electronics are already covered by international IEC standards which specify new flexible materials and printing technologies to produce flexible wearables as well as dealing flexible and stretchable semiconductor devices.
Other than batteries for wearables, there are possibilities for energy harvesting by body motion, heat or sweat to have self-powered devices. The benefits are obvious: no need for any battery, whether big or small and, on the face of it, using the human body as a source of power appears to be especially environmentally friendly. But researchers are struggling to be able to meet the energy demands of existing wearable applications using energy harvesting techniques. Low energy levels, low energy efficiency and frequent power interruptions are challenges that need to be overcome.
Piezoelectric vibration energy harvesting is the preferred method for use with wearable devices and there are already IEC standards which address piezoelectric, dielectric and electrostatic devices, and also methods for evaluating the performance of vibration-based piezoelectric energy harvesting devices.

More information may be seen e.g. at this site 

(This article is based on articles in IEC’s etech newsletters and edited by T.Sollie)