Scientists at the UChicago developed a hydrogel semiconductor having the flexibility and water-compatible properties of hydrogels and electronic functionalities of semiconductors to transform bioelectronic applications.
The newly developed hydrogel semiconductor material developed by scientists of the University of Chicago’s Pritzker School of Molecular Engineering (UChicago PME) is a gel-like substance that resembles a jellyfish in water yet retains strong semiconductive properties necessary to communicate effectively with living tissue. In particular, it boasts impressive tissue-level flexibility, stretchability up to 150% strain, and substantial charge mobility, making it highly suitable for applications such as pacemakers, biosensors, and drug delivery devices. By addressing these needs, the product holds significant interest for medical device developers, bioengineers, and healthcare providers seeking to improve patient outcomes. “When making implantable bioelectronic devices, one challenge you must address is to make a device with tissue-like mechanical properties,” explained Yahao Dai, Ph D student & lead author, UChicago PME.
The traditional approach to creating hydrogels relies on dissolving materials in water before gelling them, a method that is incompatible with semiconductors, which do not dissolve in water. However, the PME team developed an alternative method called solvent exchange, in which the semiconductors are dissolved in an organic solvent that mixes with water. This organic solution is then transformed into a gel, and the gel is finally soaked in water, allowing the organic solvent to be replaced by water, converting it to a hydrogel. Dai noted, “We started to think, ‘Okay, let’s change our perspective,’ and we came up with a solvent exchange process.”
With a structure that integrates both hydrogel and semiconductor properties, this material addresses key challenges of interfacing with living tissue. The hydrogel’s porosity allows for the transport of nutrients and chemicals, promoting efficient biomolecule diffusion. “It has very soft mechanical properties and a large degree of hydration similar to living tissue,” said Sihong Wang, assistant professor, UChicago PME underscoring the material’s potential in bioengineering.
Beyond compatibility with tissue, the hydrogel-semiconductor combination also reduces immune responses and inflammation, enabling superior biosensing and light-responsive capabilities, such as in light-operated pacemakers.
