Sticking an implantable sensor to the surface of a beating heart usually requires suturing around the periphery of the sensor or copious amounts of adhesive layered between the sensor and the heart. In both cases, such a sensor rarely has tight, uninterrupted contact with heart tissue, limiting the data that clinicians can collect on a patient’s heart function.
To solve this challenge, researchers at the University of Chicago’s Pritzker School of Molecular Engineering have designed a new adhesive semiconductor that can stick tightly to the moist, pliable surfaces of living tissues, including the heart. The semiconductor, described in the journal Science, allows tissue-adhesive properties for transistor-based biosensors.
“This is the first semiconductor and transistor that has bioadhesion as an intrinsic property — you don’t need organ-invasive stitches, staples, or glue to stick this onto a tissue,” said Sihong Wang, assistant professor at Pritzker Molecular Engineering, who led the research. “This is going to open up all sorts of new possibilities for biosensing.” Wang also holds a joint appointment at Argonne National Laboratory.
Wang’s lab at PME focuses on developing new materials to underpin a full suite of devices that interface with the human body for health monitoring. Some of their prior research has led to stretchable, flexible computer chips that can analyze health data, as well as stretchable displays to integrate into wearable electronics.
But Wang thought more work was needed to revolutionize the biosensors that carry out the first step in this workflow: collecting information from internal organs to send to the chips and displays.
Previously developed biosensors, he said, were not very good at adhering tightly to living organs. This meant the data they provided was inconsistent or spotty.
“A key step for getting information from anywhere inside the human body is transducing the signal from a tissue to a device, and the more closely your device can conform and adhere to a tissue surface, the more effective that signal transduction will be,” explained Nan Li, a Ph.D. student in Wang’s lab, who is the first author of this work.
In addition to constantly moving and having the ability to grow or shrink, most human organs are constantly moist.
“Everyone knows from their own life experience that if you try to stick a piece of tape onto a dry surface, it can adhere strongly,” said Wang. “But try to stick the same tape onto a wet surface and it becomes much harder.”
—Sam Marsden
