Biosensors perform front-line duty with health tech wearables. We’ve written about enabling technologies that improve or extend the use of sensors in the past, including stretchable sensors, optical sensors, and even sensors fabricated from graphene putty. We’ve also covered ingestible sensors that detect and signal patient medication compliance and ingestibles that monitor opioid use. Implants of any sort raise questions about possible deleterious effects of foreign objects placed in the body. Once a device is ingested or implanted, removal can require an invasive procedure.

Researchers at the Nguyen Research Group at the University of Connecticut developed a biodegradable pressure sensor that dissolves over time, obviating the need to retrieve it. The engineers published their research in the Proceedings of the National Academy of Sciences. The impetus for the sensor development was to find a replacement for existing implanted pressure sensors that contain components that could become toxic.

Using materials already deemed medically safe by the FDA for use with sutures, bone grafts, and medical implants, the UCONN team developed a sensor that does not require removal surgery. The engineers treated a polymer film to give it piezoelectric properties so that it would emit a signal when bent. Tested in a mouse, the prototype sensor was five millimeters long, five millimeters wide, and 200 micrometers thick. It emitted reliable contraction readings for four days before dissolving into its organic components. After implanting, the sensor caused only minor inflammation in surrounding tissue, which returned to its pre-implant state in four weeks.

Much more work will be required, but the team sees potential applications in monitoring glaucoma, heart disease, lung disease, brain swelling and bladder cancer. Electrical stimulation for tissue regeneration is another possible application.