Yes, you read that right. The California start-up is developing batteries that can be printed cheaply using industrial screen printers, while staying flexible and rechargeable. Obviously targeting wearable devices, the company has focused on making their batteries safe for on-body applications, and what they’ve managed to achieve so far are batteries that can deliver enough current for low-power wireless communications sensors, even in small formats.
Unlike what currently powers our smartphones and laptop computers, Imprint Energy’s batteries are powered mainly by zinc, using a solid polymer electrolyte (developed by company cofounder Christine Ho) to avoid the problem of shorting due to zinc’s tendency to form dendrites in water-based solutions. With the solid polymer electrolyte, Imprint Energy’s batteries are more stable, and can hold greater capacity for recharging.
Typical thin-film lithium batteries are rechargeable, but have limited capacity and contain a reactive element while being expensive to manufacture. Printed batteries on the other hand, are non-rechargeable but are cheap to make, and offer higher capacities. They also typically use zinc, which has allowed Imprint Energy manufacturing advantages – zinc’s environmental stability means they don’t need the protective equipment required for oxygen-sensitive lithium batteries.
Because there is yet to be a standard for testing flexible batteries, the company has been benchmarking their batteries against other commercially available flexible batteries using their own test rig. And what Imprint Energy has found is that most batteries fail after less than 1,000 bending cycles, while their own batteries have stayed stable.
The company has been in talks about use of its batteries in clothing and parts of the body, and have recently begun a project funded by the U.S military to make batteries for sensors that would monitor the health status of soldiers. Given the craze over wearables these days, it certainly is heartening to note that a safe, non-toxic means of powering them is on the way.