This week we learned about an exciting new liquid metal-infused polymer, made with a gallium-indium alloy, which can be used to form circuits that heal themselves after being damaged. Today, Eric Markvicka and I wrap up our conversation.
Jim: Where do you see this field of experimentation taking you next??
Eric: Electrical self-healing is an important property, but the material does not heal itself mechanically after damage. A next step for us will be to engineer and study a soft conductive material that is capable of both electrical and mechanical self-healing without requiring manual intervention.
Jim: That does seem like a logical next step.
Eric: If we accomplish this, then we can get even closer to engineering machines and electronics that match the extraordinary resilience of natural biological tissue.
Jim: That sounds perfect for applications where humans are not present. By the way, I understand the liquid metal circuits can be used as pressure sensors too. What would be the advantages of a liquid metal-embedded elastomer sensor?
Eric: The liquid metal (LM) elastomer composite wouldn't be great for use as a traditional pressure sensor. The conductive wiring is observed to have a negligible electro-mechanical coupling. Stretching to 50% strain, the maximum increase in resistance is less than 10%. In contrast, for a microfluidic channel of liquid metal you would expect an increase of 125% for the same strain. Such a characteristic increase in circuit resistance is undesirable for most circuit applications and power transmission.
Jim: Are there any other types of sensing applications this could be used for?
Eric: Potentially, the LM-elastomer composite could be used to detect damage (cutting, tearing, or puncture) by monitoring the local changes in electrical conductivity.
Jim: I think there will be a few readers out there thinking about new ways to use this fascinating material. Eric, thank you so much for your time.
Eric: Thanks again for showing interest in our work!
(The electrically self-healing liquid metal-elastomer composite is detailed in Nature Materials)