Highly stretchable, transparent and room-temperature self-healable polydimethylsiloxane elastomer for bending sensor.

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Highly stretchable and self-healable elastomers are crucial for advanced applications like electronic skin and wearable devices.
• Existing materials often face limitations in terms of synthesis simplicity, healing efficiency, or performance in diverse environments.

Purpose of the Study:

• To develop a straightforward, room-temperature synthesis method for polydimethylsiloxane (PDMS) elastomers with high stretchability and self-healing capabilities.
• To investigate the self-healing mechanisms and performance of the synthesized PDMS elastomers under various conditions.
• To demonstrate the practical application of these elastomers in fabricating functional sensors for human motion detection.

Main Methods:

• A one-pot, two-step synthesis approach was employed, reacting aminopropyl-terminated PDMS with isophorone diisocyanate, followed by chain extension with terephthalaldehyde.
• Characterization of the synthesized elastomer's mechanical properties, including stretchability and transparency.
• Evaluation of self-healing efficiency at room temperature, in water, and in artificial sweat.
• Fabrication and testing of a multiwalled carbon nanotube (MWCNT-OH) based bending sensor using the self-healing elastomer for human motion detection.

Main Results:

• The synthesized PDMS elastomer achieved 1670% stretchability and 92% transmittance.
• Excellent self-healing efficiency of 95% was observed after 24 hours at room temperature, with significant healing in water (89%) and artificial sweat (78%).
• A functional triple-layer bending sensor was successfully fabricated and demonstrated effective human motion detection, with rapid recovery under sunlight irradiation.

Conclusions:

• The developed one-pot, two-step method provides a simple and scalable route to highly stretchable, transparent, and room-temperature self-healing PDMS elastomers.
• The elastomer's robust self-healing properties, attributed to dynamic hydrogen bonds, reversible imine bonds, and flexible SiO chains, make it suitable for demanding applications.
• The successful fabrication and application of the sensor highlight the potential of these advanced elastomers in wearable electronics and functional devices.