Integrated microelectromechanical systems: A perspective on MEMS in the 90s

The author examines the opportunities and challenges facing the development of integrated microelectromechanical systems (MEMS). It has now been established that micromachined sensors can be produced with high yield and merged with integrated electronics, both in monolithic chips and in hybrid multichip assemblies. For some types of sensors, accuracy is approaching 16 bits, and VLSI interface circuits are being defined to allow features such as self-testing and digital compensation to be used. Continuing technical challenges for full MEMS include the development of processes capable of three-dimensional microstructures, improved drive technologies for microactuators, better approaches to packaging and microassembly, and the creation of workstation-based simulators, operating from rich databases of materials and structural information. Formidable challenges in non-technical areas are also posed, including the definition of appropriate applications for MEMS and the accomplishment of the needed changes in established host systems to take advantage of their features. These issues are illustrated by several devices currently being developed, including integrated neuroelectronic interfaces, pressure and flow sensors, microvalves, and scan tips for near-field microscopy