The third seminar in the 2015 Solid Mechanics@Stanford series will be:
Professor Zhigang Suo
Allen E. and Marilyn M. Puckett Professor of Mechanics and Materials
Hydrogel as tough water
What can we do if water is a tough solid? A hydrogel aggregates water and a polymer network. The polymer network makes the hydrogel a stretchable solid, but water retains its exceptional physical and chemical properties. Several recent findings show that hydrogels can achieve properties and applications well beyond previously imagined. Most existing hydrogels, like Jell-O and tofu, are fragile and dry out in open air. We make hydrogels as tough as rubber, and retain water in low-humidity environment. We use hydrogels to mimic the function of axons, transmitting electrical signals over long distances and at high speeds. We make a loudspeaker that plays music over entire audible range, and transmits light of all colors. We demonstrate an ionic skin — a stretchable, transparent, large-area sheet of distributed sensors. We show that hydrogels outperform existing fire-retarding materials. This talk describes the mechanics and chemistry of these materials and applications.