[dropcap]I[/dropcap]magine that you are designing clothing with embedded electronics. A major issue in such a design will be the availability of electronics that can bend, flex and stretch. Despite progress in flexible electronics, the question still remains as to how to power up the electronics? The batteries in flexible electronics need to be stretchable.
The good news is that batteries can be made extremely stretchable as has been recently demonstrated by a team from University of Illinois and North Western University. In fact, the demonstrated battery has an astonishingly three hundred percent stretchability! The secret is the use of thin, low modulus silicone elastomers as substrates, with a segmented design in the active materials, and unusual ‘self-similar’ interconnect structures between them. This has been detailed in the Feb. 26, 2013 issue of the journal Nature Communications.
In simpler terms, serpentine metal wires have been used to interconnect this Li-ion battery electrodes. These metal wires have more wavy wires inside. Normally these wires do not need much space. On stretching, they unfurl giving the battery enough ‘elasticity’ to stretch up to three times of its normal size.
This battery can be recharged wirelessly and thus eliminating the need of physical contact with an external power source. There are many interesting potential applications for such stretchable batteries – Implants, cyber skin for robotic devices, electronic nervous systems, etc.
Get ready to welcome the cyborg!