Medical implants such as pacemakers could get flexible, organic batteries, thanks to a new design from Queen’s University Belfast.
Researchers have designed an alternative to the rigid metal-based batteries that power implanted devices such as pacemakers and defibrillators, and can cause patients discomfort.
Geetha Srinivasan and a team of researchers from the university’s Ionic Liquid Laboratories have developed a flexible supercapacitor with a longer cycle life that could be used instead. It is made of non-flammable electrolytes and organic composites, and so it’s safer for the body and can be easily decomposed.
“The implant under the skin is wired to the device and can cause patients discomfort as it rubs against the skin. For this reason batteries need to be compatible to the human body and ideally we would like them to be flexible so that they can adapt to body shapes,” said Srinivasan.
“At Queen's University Belfast we have designed a flexible energy storage device, which consists of conducting polymer – biopolymer composites as durable electrodes and ionic liquids as safer electrolytes. The device we have created has a longer life-cycle, is non-flammable, has no leakage issues and, above all, it is more flexible for placing within the body.”
Niko Munzenrieder, a lecturer in sensor technology at the University of Sussex who was not involved in the research, told Professional Engineering that capacitors like this device were inherently safer than batteries. “Both can store energy but in entirely different ways,” he explained. “A battery is a chemical device, which is to some extent bad for biomedical applications, because it contains reactive chemicals and it has to ensure these do not react with the body. A capacitor stores energy in an electric field, which is basically physics, and in my opinion is safer when it comes to medical applications.”
The organic storage technology could also make wearable electronics and personal devices such as smartphones more flexible. “The performance of a capacitor strongly depends on the performance of the employed dielectric layer,” said Munzenrieder. “Here they used an electrolyte, and if they managed to fabricate a bendable, organic layer with high specific capacitance and low leakage current (which is made from cheap biocompatible materials) it would be very interesting not only for capacitors but also for other flexible devices such as transistors.”