An Introduction to Microelectromechanical Systems Engineering The Sandbox: Materials for M E M S devices are made of n-type and p-type bismuth telluride elements, and are used to cool high-performance microprocessors, laser diodes, and infrared sensors. Peltier devices have proven difficult to implement as micromachined thin film structures. In the Seebeck effect, named for the scientist who made the discovery in 1822, a temperature gradient across an element gives rise to a measurable electric