Self-Healable, Degradable, and Reprocessable Lignin-based Polyurethane Elastomer for a Flexible Strain Sensor
Category
Topical Literature Review
Department
Material Science
Student Status
Graduate
Research Advisor
Dr. Ram Gupta
Document Type
Event
Location
Student Center Ballroom
Start Date
10-4-2025 2:00 PM
End Date
10-4-2025 4:00 PM
Description
Flexible strain sensors have attracted great attention for their important application potential in soft robots, wearable devices, electronic skin, and human-computer interaction. However, there are still challenges such as the loss of service life due to external forces and the production of electronic waste that need to be solved. Herein, a self-healable, degradable, and reprocessable lignin-based polyurethane (LPU) elastomer was synthesized for a flexible strain sensor. Owing to the formation of a crosslinking network by lignin and the reinforcement role of unreacted lignin, the tensile strength and elongation at break of the LPU elastomer reached 2.72 MPa and 712%, respectively. The plentiful hydrogen and disulfide bonds endowed the elastomer with not only good self-healing capability but also superior reprocessing performance. Importantly, the elastomer was able to be completely degraded within only 2 hours in a 1 mol/L NaOH water/ethanol solution. The LPU elastomer-based flexible strain sensor with liquid metal (LM) as the conductive material was successfully applied to detect various human motions and could restore its sensing function with the healing of the substrate and reconnection of the LM conductive layer. Moreover, the LM in the discarded sensor could be easily recycled to prepare the sensor after the degradation of the LPU substrate. The functional and environmentally friendly bio-based elastomer will greatly promote the sustainable development and application of flexible electronics.
Self-Healable, Degradable, and Reprocessable Lignin-based Polyurethane Elastomer for a Flexible Strain Sensor
Student Center Ballroom
Flexible strain sensors have attracted great attention for their important application potential in soft robots, wearable devices, electronic skin, and human-computer interaction. However, there are still challenges such as the loss of service life due to external forces and the production of electronic waste that need to be solved. Herein, a self-healable, degradable, and reprocessable lignin-based polyurethane (LPU) elastomer was synthesized for a flexible strain sensor. Owing to the formation of a crosslinking network by lignin and the reinforcement role of unreacted lignin, the tensile strength and elongation at break of the LPU elastomer reached 2.72 MPa and 712%, respectively. The plentiful hydrogen and disulfide bonds endowed the elastomer with not only good self-healing capability but also superior reprocessing performance. Importantly, the elastomer was able to be completely degraded within only 2 hours in a 1 mol/L NaOH water/ethanol solution. The LPU elastomer-based flexible strain sensor with liquid metal (LM) as the conductive material was successfully applied to detect various human motions and could restore its sensing function with the healing of the substrate and reconnection of the LM conductive layer. Moreover, the LM in the discarded sensor could be easily recycled to prepare the sensor after the degradation of the LPU substrate. The functional and environmentally friendly bio-based elastomer will greatly promote the sustainable development and application of flexible electronics.
