Scientists have developed a stretchable 3D "smart bandage" that can help wirelessly monitor signals, from respiration, to eye movement, to heart and brain activity, as well as a robotic arm.
 

When worn on the chest or stomach, it records heart signals like an electrocardiogram (ECG). On the forehead, it records brain signals like a mini EEG sensor, and when placed on the side of the head, it records eyeball movements.When worn on the forearm, it records muscle activity and can also be used to remotely control a robotic arm. The smart bandage also monitors respiration, skin temperature and body motion, the research showed.

"This device is like a 'master of all trades'. We picked high quality, robust sub-components -- the best strain sensor we could find on the market, the most sensitive accelerometer, the most reliable ECG sensor, high quality Bluetooth, etc -- and developed a clever way to integrate all these into one stretchable device," said Yang Li, graduate student at the University of California-San Diego. 

The novel device, detailed in the journal Nature Electronics, consists of four layers of interconnected stretchable, flexible circuit boards.Each layer is built on a silicone elastomer substrate patterned with an 'island bridge' design, where each 'island' is a small, rigid, electronic part (sensor, antenna, Bluetooth chip, amplifier, etc) that is attached to an elastomer.The islands are connected by stretchy 'bridges' made of thin, spring-shaped copper wires, allowing the circuits to stretch, bend and twist without compromising electronic function. 

So far, the smart bandage can last for more than six months without any drop in performance, stretchability or flexibility.It can communicate wirelessly with a smartphone or laptop up to 10 metres away. The device runs on a total of about 35.6 milliwatts, which is equivalent to the power from 7 laser pointers, the researchers said.