Abstract There has been significant recent interest in applying microelectromechanical (MEMS) technology to miniaturization of relays for a variety of applications in the telecommunications, test equipment, and automotive fields. Mechanical switches with metal-to-metal contact are still preferred where low insertion loss and high off-isolation are required, particularly in cost-sensitive applications. MEMS technology offers great promise in addressing the need for smaller electromechanical relays, and may bridge the performance and economic gaps between conventional electromechanical technology and solid state devices. In this paper we cover some general MEMS approaches to building a microrelay and the challenges and trade-offs involved. We also discuss specific devices we have explored using a new MEMS thermal actuation.