Hydrogel Semiconductor Material Emerges as an Ideal Bioelectronic Interface

In a recent issue of Science, a research team from the University of Chicago’s Pritzker School of Molecular Engineering showcased a breakthrough in the field of interfacial bioelectronics: the development of a new hydrogel material with remarkable semiconductor capabilities. This innovative blue gel can float in water like a jellyfish while also providing advanced semiconductor functionality, enabling effective information transmission between biological tissues and machines.
The researchers designed this hydrogel to facilitate data transfer between living tissues and electronic devices, supporting both implantable medical devices and non-invasive applications. Ideally, materials that connect electronic components with biological tissues should be soft, stretchable, and water-compatible—qualities typical of hydrogels. However, traditional semiconductor materials are generally rigid, brittle, and non-hydrophilic, which prevents them from dissolving in water like hydrogels and limits their use in bioelectronic devices such as pacemakers, biosensors, and drug delivery systems.
This new material exhibits a tissue-like modulus of up to 81 kPa, a stretchability of up to 150%, and a high carrier mobility of 1.4 cm²/Vs. These properties suggest that this material, combining both semiconductor and hydrogel characteristics, meets all the essential requirements for an ideal bioelectronic interface.
To create a close biological interface, implantable bioelectronic devices must adapt to surrounding tissue movement. This requirement led the team to develop a semiconductor that integrates seamlessly with hydrogel. Traditional hydrogels are formed by dissolving materials in water, but semiconductors are usually water-insoluble.
To address this, the researchers developed a solvent exchange method. Instead of dissolving the semiconductor in water, they used a water-compatible organic solvent and combined the dissolved semiconductor with a hydrogel precursor to create an organic gel. Soaking this gel in water then dissolves the organic solvent, allowing water to permeate the structure and resulting in a material fit for various polymer semiconductors.
Notably, this novel hydrogel outperforms traditional hydrogels and semiconductor materials in several aspects, offering enhanced biological functionality and delivering a more balanced, effective result.
While the research primarily addresses challenges faced by implantable devices like biochemical sensors and cardiac pacemakers, the material holds great promise for non-invasive applications, such as more accurate skin data reading and improved wound care. Its ultra-soft mechanical properties and high water content closely resemble those of living tissues, and its porous nature supports the transport of nutrients and chemicals. When these attributes are combined, the new hydrogel becomes a highly promising material for tissue engineering and drug delivery applications.