Tough, flexible silicone sensor for wearable biomonitoring

Technology News | March 9, 2020

By Rich Pell

Sensing / Conditioning Wireless Communications Materials & processes Electromechanical Wearables Analog Medical Electronics Flexible Electronics

Developed using 3D printing and nanotechnology, the sensor combines silicone rubber with ultra-thin layers of graphene in a material suited for making wristbands or insoles in running shoes. When the rubber material bends or moves, electrical signals are created by the highly conductive, nanoscale graphene embedded within its engineered honeycomb structure.

“Silicone gives us the flexibility and durability required for biomonitoring applications, and the added, embedded graphene makes it an effective sensor,” says Ehsan Toyserkani, research director at the Multi-Scale Additive Manufacturing (MSAM) Lab at Waterloo. “It’s all together in a single part.”

The rubber-graphene material is extremely flexible and durable in addition to being highly conductive, say the researchers.

“It can be used in the harshest environments, in extreme temperatures and humidity,” says Elham Davoodi, an engineering PhD student at Waterloo who led the project. “It could even withstand being washed with your laundry.”

Fabricating a device with such complex internal features, say the researchers, is only possible using state-of-the-art 3D printing equipment and processes. The material and the 3D printing process also enable custom-made devices to precisely fit the body shapes of users, while also improving comfort compared to existing wearable devices and reducing manufacturing costs due to simplicity.

The rubber-graphene sensor, say the researchers, can be paired with electronic components to make wearable devices that record heart and breathing rates, register the forces exerted when athletes run, allow doctors to remotely monitor patients, and numerous other potential applications. For more, see “3D-Printed Ultra-Robust Surface-Doped Porous Silicone Sensors for Wearable Biomonitoring.”