The inventors have created a way to integrate stretchable conductors, rigid electronic components, drug-delivery channels, and reservoirs into biocompatible and tough hydrogel matrices that contain significant amounts of water.
Hydrogels are hydrophilic polymeric materials capable of holding large amounts of water in their three-dimensional networks. Due to their high water content, mechanical softness, and diffusion of waterborne molecules, hydrogels closely resemble natural living tissue. These properties, along with their good biocompatibility and ease of fabrication, make hydrogels desirable for use in a number of biomedical applications. However, while hydrogels possess many beneficial properties, they typically have some limitations in biomedical applications-mainly poor mechanical properties and weak hydrogel-solid interfaces. For example, formation of weak hydrogel-solid interfaces results in a failure to integrate the soft hydrogel and rigid components with adequate functionality and reliability. Such robust hydrogel-solid hydrogel structures have great potential of addressing several issues in various biomedical applications. Robust hybridization of rigid electronic components into a hydrogel matrix can provide a useful platform for wearable devices with higher compatibility. Also, highly water containing hydrogels will act as promising prolonged drug delivery platforms by acting as a drug reservoir as well as a diffusion medium in biomedical applications.
The Inventors have created tough biocompatible hydrogels that can be used in drug delivery components, stretchable or otherwise deformable conductors, and rigid electronic components. The resultant hydrogel-based electronics and devices are mechanically robust, highly stretchable, biocompatible, and capable of multiple novel functions. The design of tough hydrogels relies on a combination of long-chain polymer networks that are highly stretchable, and other components (such as other polymer networks) that can dissipate significant mechanical energy under deformation. The compliant hydrogel matrix can accommodate both deformable (e.g., wavy wires and channels) and rigid (e.g., silicon chips) components embedded in or attached on it, even when the hydrogel electronics and devices are highly deformed. Surface functionalization (e.g., coating and silanation) of the functional components can give tough covalent bonding to the hydrogel, which is critical to functionality and reliability of hydrogel electronics and devices. The Inventors have demonstrated novel applications of hydrogel electronics and devices including a soft, wet, transparent, and stretchable LED array, and a smart wound dressing capable of sensing temperatures of various locations on the skin, delivering different drugs to these locations, and subsequently maintaining sustained releases of drugs. Furthermore, they also demonstrated the integration of drug delivery channels and reservoirs within the hydrogel. These drug delivery channels are capable of releasing drug over time at deformed and un-deformed states.
- Robust and reliable hybridization of solid functional components into soft and tough hydrogels that can endure large and cyclic deformation
- A smart wound dressing capable of delivering drugs at various locations on the human skin according to the temperature measured at those locations.
- A drug delivery reservoir within the hydrogel capable of slow, and sustained release of the drug