Not only are the devices custom 3D-printed and based on body scans of wearers, but they can operate continuously using a combination of wireless power transfer and compact energy storage.
“There’s nothing like this out there,” said Philipp Gutruf, assistant professor of biomedical engineering, a member of the University of Arizona’s BIO5 Institute. “We introduce a completely new concept of tailoring a device directly to a person and using wireless power casting to allow the device to operate 24/7 without ever needing to recharge.”
Current wearable sensors face various limitations. Smartwatches, for example, need to be charged, and they can only gather limited amounts of data due to their placement on the wrist. By using 3D scans of a wearer’s body, which can be gathered via methods including MRIs, CT scans and even carefully combined smartphone images, Gutruf and his team can 3D-print custom-fitted devices that wrap around various body parts. The ability to specialize sensor placement allows researchers to measure physiological parameters they otherwise couldn’t.
"If you want something close to core body temperature continuously, for example, you’d want to place the sensor in the armpit. Or, if you want to measure the way your bicep deforms during exercise, we can place a sensor in the devices that can accomplish that,” said Tucker Stuart, a doctoral student in biomedical engineering and first author on the paper. “Because of the way we fabricate the device and attach it to the body, we're able to use it to gather data a traditional, wrist-mounted wearable device wouldn't be able to collect.”
As the biosymbiotic devices are custom fitted to the wearer, they’re also highly sensitive. Gutruf’s team tested the device’s ability to monitor parameters including temperature and strain while a person jumped, walked on a treadmill, and used a rowing machine. In the rowing machine test, subjects wore multiple devices, tracking exercise intensity and the way muscles deformed with fine detail. The devices were accurate enough to detect body temperature changes induced by walking up a single flight of stairs.
The biosymbiotic device uses no adhesive, and it receives its power from a wireless system with a range of several meters. The device also includes a small energy storage unit, so that it will function even if the wearer goes out of the system’s range, including out of the house.
“These devices are designed to require no interaction with the wearer,” Gutruf said. “It’s as simple as putting the device on. Then you forget about it, and it does its job.”