Tiny sensors and printed electronics make it possible to create small, flexible, wearable Health Tech devices. These devices need electricity to operate, which means that they need a way to store the energy until needed. Most batteries are rigid devices, and often rely on liquid electrolytes that are toxic and can even catch fire spontaneously.
Researchers at Drexel University are working on a new supercapacitor technology. A supercapacitor has an energy capacity similar to a battery, but can be recharged — and discharged — much faster. They also can survive more discharge/recharge cycles. Many supercap designs still rely on toxic liquid electrolytes. The Drexel team has created a system that relies on an electrolyte in gel form. A flexible mat of carbon nanofibers then absorbs this gel to create a supercap. The mat is created in an interesting way: electrospinning. They start with a carbon-based polymer precursor, and then extrude it it through a rotating electric field. The process is similar to that used to create cotton candy, and results in a highly porous, strong, and flexible mat that can hold the electrolyte gel. It is lightweight, and costs about 20% less to fabricate that other designs.
In order for wearable devices to become commonplace, they must be convenient and unobtrusive. Supercap technology like this could go along way towards solving the energy storage part of the equation.