A bimetallic strip is a device made of two different metals bonded together. When the temperature changes, the metals expand at different rates, causing the strip to bend. This bending can be used to measure temperature or activate switches in various applications, such as thermostats. Bimetallic strips are commonly found in household appliances, like thermostats, where they help regulate temperature. They are also used in clocks and sensors to convert temperature changes into mechanical movement, making them essential in many everyday devices.