Researchers at MIT have developed an adhesive bandage with a sticky gel-like material that can incorporate temperature sensors, LED lights, and other electronics. It can also incorporate minuscule drug-delivering reservoirs and channels.
The researchers created a “smart wound dressing” that responds to changes in temperature by releasing medicine. It also lights up if the medicine is running low. The hydrogel matrix, which makes up the dressing, stretches with the body, keeping the embedded electronics functional and intact. Associate professor Xuanhe Zhao, in MIT’s Department of Mechanical Engineering developed the hydrogel matrix which he detailed last month. The mostly water hydrogel is a rubbery material that can bond strongly to surfaces such as gold, titanium, aluminum, silicon, glass, and ceramic.
The team published a new paper in the journal Advanced Materials, describing how they embedded various electronics within the hydrogel including semiconductor chips, conductive wires, temperature sensors, and LED lights. Zhao asserts that the electronics coated in hydrogel may also be used inside the body. Such electronics could be used as implantable, biocompatible glucose sensors, or even neural probes.
Zhao said, that it is very desirable for materials to be soft and stretchable to fit the human body for applications such as health care monitoring or drug delivery.
The co-authors on the paper include 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.
The team mixed water with a small amount of selected biopolymers to form soft, stretchy materials. The materials have a stiffness of 10 to 100 kilopascals, which is about the range of human soft tissues. The group also devised a method to strongly bond the hydrogel to various nonporous surfaces. They embedded a stretchable titanium wire that managed to maintain constant electrical conductivity after being stretched multiple times.
Zhao also embedded an array of LED lights in a sheet of hydrogel. The array continued working, even when stretched across highly deformable areas such as the knee and elbow.
Finally, the group embedded electronic components within a sheet of hydrogel to create a “smart wound dressing.” The wound dressing was comprised of regularly spaced temperature sensors and tiny drug reservoirs. The researchers also inserting patterned tubes and drilled tiny holes through the matrix to deliver medicine.
They found that the dressing continued to monitor skin temperature and release drugs according to the sensor readings even when highly stretched. Yuk noted that one immediate application of the technology may be as an on-demand treatment for burns or other skin conditions.
Zhao is currently exploring hydrogel’s potential as a carrier for glucose sensors and neural probes.
Funding for this research in part came from the MIT Institute for Soldier Nanotechnologies, the Office of Naval Research, and the National Science Foundation.
