New hydrogel ‘Band-Aid’ senses, lights up, delivers medicine

There could soon be a day where the adhesive bandage you use to cover the cut on your arm or the gash in your leg comes with built-in temperature sensors, LED lights, drug-delivery channels, and other electronics, and it’s all thanks to the efforts of a team of MIT engineers.

This next-gen wound dressing, affectionately dubbed “the Band-Aid of the future” in a statement from the university, would be able to release medicine in response to changes in the patient’s skin temperature, and would light up if its supply of drugs was close to running out.

The bandage is made from a hydrogel matrix designed by Xuanhe Zhao, the Robert N. Noyce Career Development Associate Professor at MIT’s Department of Mechanical Engineering. It would also stretch with the body, allowing embedded electronics to remain intact and continue functioning even when applied to the elbow, knee, or other highly-flexible body parts.

“Since hydrogels can have very similar properties as human tissues (e.g., softness, wetness, and bioactivity), they provide ideal matrices to encapsulate electronic devices that interface with the human body,” Zhao explained to redOrbit via email. “However, common hydrogels are brittle, barely stretchable, and adhere weakly to electronic materials.”

Adding biopolymers made the hydrogel soft and flexible

To overcome those shortcomings, the MIT professor, graduate students Shaoting Lin, Hyunwoo Yuk, German Alberto Parada, postdoc Teng Zhang, Hyunwoo Koo from Samsung Display, and Cunjiang Yu from the University of Houston set out to develop a type of the materials that was “robust, stretchable, and biocompatible” but still able to bond to electronics.

First, they came up with new design in which they added small amounts of selected biopolymers into water to create a material that is soft and elastic, and then they came up with a way to allow this hydrogel to bond to a variety of nonporous surfaces, MIT explained in a statement.

Their findings, published recently in the journal Advanced Materials, involved taking the rubber-like substance—which was still primarily made from water and could strongly bond with silicon, gold, aluminum, glass and other surfaces—and embedding different kinds of electronics (such as conductive  wires, semiconductors, temperature sensors, and more) within the hydrogel.

The new wound dressing is “a proof of concept” and “a demonstration of a device that integrates sensors and electronics in a stretchable, robust and biocompatible hydrogel,” Zhang told redOrbit on Monday. The bandages are “soft, wet and stretchable” and can “sense temperature changes at various locations and deliver drugs accordingly,” he added, and could be the start of a new era of stretchable hydrogel electronics and devices in a variety of different fields.

Specifically, the team is currently examining whether or not the hydrogel could potentially be used in glucose sensors or neural probes, allowing them to be effective over long periods of time. Such hydrogel-sensor systems, the authors claim, would likely be robust and effective over long periods of time without needing replacement.

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Feature Image: Melanie Gonick/MIT

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