Dr. Chao Wang, an assistant professor of chemistry at the University of California, Riverside, states that when designing the material, its high stretchability was expected because the team intentionally incorporated energy-dissipation sites into the polymers. Wang is co-author of an article published in the journal Nature Chemistry.
Muscle-like twitch
The material is made of a network of elastic polymers — a stretchable plastic-like substance — crosslinked together. The researchers also jolted the material with an electrical field and found that it responds with a muscle-like twitch or pulse. The material can self-repair any gaps or punctures at temperatures as low as -20 degrees Celsius since it bonds to itself.The polymers become linked together like a big net through the metal ions and the ligands, says Dr. Zhenan Bao, professor of chemical engineering at Stanford University and lead author of the study.
Each metal ion binds to at least two ligands, so if one ligand breaks away on one side, the metal ion may still be connected to a ligand on the other side. “When the stress is released, the ion can readily reconnect with another ligand if it is close enough.”