The bandage is getting a major update for the 21st century, with the latest advances coming from engineers at MIT. A team there has developed a gel-like material that is sticky, stretchable and can be combined with sensors, lights and drug delivery systems to create a complete "smart wound dressing."
Imagine a Band-Aid that stretches with the movements of the body to adhere perfectly to the area around a wound and can administer a dose of medication to a wound as needed in response to skin temperatures that it measures via embedded sensors. When the bandage is running low on medicine, it can notify a physician or patient via a light.
MIT professor Xuanhe Zhao says it's all possible thanks to a unique hydrogel matrix he designed that has rubbery properties but is mostly made up of water and able to create a strong bond with surfaces including metals, silicon, glass and ceramic. Because it's water-based it's also compatible with skin.
"Electronics are usually hard and dry, but the human body is soft and wet. These two systems have drastically different properties," Zhao says. "If you want to put electronics in close contact with the human body for applications such as health care monitoring and drug delivery, it is highly desirable to make the electronic devices soft and stretchable to fit the environment of the human body. That's the motivation for stretchable hydrogel electronics."
His team has published a paper in the journal Advanced Materials that details how they embedded components like wires, semiconductor chips, LED lights and temperature sensors in the hydrogel for use on skin as well as potential implants inside the body, something that sets it apart from other "smart-bandage" products we've seen lately that use more conventional materials.
The design mixes water with certain biopolymers to avoid the typical shortcomings of synthetic hydrogels, which Zhao says tend to be more brittle and less flexible.
"It's a very versatile matrix," says co-author Hyunwoo Yuk. "The unique capability here is, when a sensor senses something different, like an abnormal increase in temperature, the device can on demand release drugs to that specific location and select a specific drug from one of the reservoirs, which can diffuse in the hydrogel matrix for sustained release over time."
Zhao is interested in next using the hydrogel as a carrier for glucose sensors inside the body as well as for neural probes in the brain.
Professor Xuanhe Zhao discusses the stretchable hydrogel in the following MIT video.