Wearable electronics can be integrated with the human body for monitoring physical activities and health conditions, for human-computer interfaces, and for virtual/augmented reality. An international team of scientists from China and the United States has developed a multifunctional wearable electronic device that can simultaneously provide full recyclability, excellent mechanical stretchability, self-healability, and reconfigurability. The team’s device can heal itself, much like real skin. It also reliably performs a range of sensory tasks, from measuring the body temperature of users to tracking their daily step counts. And it’s reconfigurable, meaning that the device can be shaped to fit anywhere on your body.
Fabrication processes and sensing performance of the multifunctional wearable electronics: (A) schematic illustration of the fabrication processes of the multifunctional wearable electronics; (B) motion tracking performance with the multifunctional device worn on the wrist; (C) indoor and outdoor body temperatures acquired using the wearable electronics mounted on the forehead (top) and comparison of measured indoor body temperatures when the wearable electronics is mounted at different locations (bottom); (D) acoustic data acquired using the wearable electronics mounted on the neck; (E) ECG data acquired using the wearable electronics when the participant is at rest (top), and after exercising for 13 s (middle) and 34 s (bottom). Image credit: Chuanqian Shi, University of Colorado, Boulder.
“If you want to wear this like a watch, you can put it around your wrist,” said senior co-author Dr. Jianliang Xiao, a researcher in the Department of Mechanical Engineering at the University of Colorado, Boulder.
“If you want to wear this like a necklace, you can put it on your neck.”
“Smart watches are functionally nice, but they’re always a big chunk of metal on a band,” said senior co-author Dr. Wei Zhang, a researcher in the Department of Chemistry at the University of Colorado Boulder.
“If we want a truly wearable device, ideally it will be a thin film that can comfortably fit onto your body.”
To manufacture their device, the scientists use screen printing to create a network of liquid metal wires.
They then sandwich those circuits in between two thin films made out of a highly flexible and self-healing material called polyimine.
The resulting device is a little thicker than a Band-Aid and can be applied to skin with heat.
It can also stretch by 60% in any direction without disrupting the electronics inside.
“It’s really stretchy, which enables a lot of possibilities that weren’t an option before,” Dr. Xiao said.
“If you slice a patch of electronic skin, all you have to do is pinch the broken areas together,” Dr. Zhang said.
“Within a few minutes, the bonds that hold together the polyimine material will begin to reform. Within 13 minutes, the damage will be almost entirely undetectable.”
“Our solution to electronic waste is to start with how we make the device, not from the end point, or when it’s already been thrown away. We want a device that is easy to recycle,” Dr. Xiao added.
The team’s work appears in the journal Science Advances.
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Chuanqian Shi et al. 2020. Heterogeneous integration of rigid, soft, and liquid materials for self-healable, recyclable, and reconfigurable wearable electronics. Science Advances 6 (45): eabd0202; doi: 10.1126/sciadv.abd0202
