The sensor, which is enabled by the biofuel cell, harvests glucose from body fluids to run. It also consists of an analog front-end circuit designed to process physiological and biochemical signals with high sensitivity.
The implantable device, say the researchers, could be manufactured cheaply through mass production and offers an alternative to popular sensors like smartwatches - which need to be recharged - or superficial patches that are worn on the skin and can't be embedded. In addition, the new sensor would also remove the need to prick a finger for testing of certain diseases, such as diabetes.
"The human body carries a lot of fuel in its bodily fluids through blood glucose or lactate around the skin and mouth," says Subhanshu Gupta, assistant professor in WSU's School of Electrical Engineering and Computer Science. "Using a biofuel cell opens the door to using the body as potential fuel."
The sensor, say the researchers, uses highly-sensitive state-of-the-art electronics that consume only a few microwatts of power and is more efficient than traditional battery-powered devices. Further, it can be powered indefinitely using the body glucose that is produced just under the skin.
The sensor's biofuel cell is also non-toxic, unlike commonly used lithium batteries, making it more promising as an implant. The biofuel cell is also more stable and sensitive than conventional such cells, say the researchers, which have been limited by unstable operation and low-voltage outputs.
Looking ahead, the researchers hope to test and demonstrate their sensor in blood capillaries, the smallest blood vessels in the body, which will require regulatory approval. They are also working on further improving and increasing the power output of their biofuel cell.
"This brings together the technology for making a biofuel cell with our sophisticated electronics," says Gupta. "It's a very good marriage that could work for many future applications."