Carrying out maintenance tasks inside a nuclear plant puts severe strains on equipment, due to extreme temperatures that are hard for components to endure without degrading. Now, researchers at MIT and elsewhere have come up with a radically new way to make actuators that could be used in such extremely hot environments.
The system relies on oxide materials similar to those used in many of today’s rechargeable batteries, in that ions move in and out of the material during charging and discharging cycles. Whether the ions are lithium ions, in the case of lithium ion batteries, or oxygen ions, in the case of the oxide materials, their reversible motion causes the material to expand and contract.
Such expansion and contraction can be a major issue affecting the usable lifetime of a battery or fuel cell, as the repeated changes in volume can cause cracks to form, potentially leading to short-circuits or degraded performance. But for high-temperature actuators, these volume changes are a desired result rather than an unwelcome side effect.
The findings are described in a report appearing this week in the journal Nature Materials, by Jessica Swallow, an MIT graduate student; Krystyn Van Vliet, the Michael (1949) and Sonja Koerner Professor of Materials Science and Engineering; Harry Tuller, professor of materials science and engineering; and five others.
This story was featured on the MIT homepage on May 9, 2017.