bimetallic strip
noun [ C ] engineering specialized uk/ˌbaɪ.mə.tæl.ɪk ˈstrɪp/ us/ˌbaɪ.mə.tæl.ɪk ˈstrɪp/
（用于恒温器等的）双金属条;双金属片
a strip, used in a thermostat, made from two different metals that grow larger by different amounts when heated, causing the strip to bend and switch a device on or off