Recent progress in micromachining technology and application in implantable biomedical systems

This paper reviews recent developments in micromachining technologies for the fabrication of microsensors, microactuators, and integrated microsystems, and illustrates their application in implantable biomedical systems. Micromachining technologies such as bulk silicon micromachining, surface micromachining and electroplating techniques are first reviewed, and the most recent advances that have been made in each of these technologies are discussed. As microsystems become more complex, these three mainstream technologies will be increasingly used and combined to build complex systems at low cost. Many of these technologies have been utilized in the development of implantable biomedical systems. These systems offer a number of difficult actuators, and electronics or a combination of them, requirements that need to be satisfied, including small size, low power, functional versatility, and stable and biocompatible packaging. New micromachining and sensor technologies have been utilized to satisfy these challenges. This paper will also review integrated implantable microsystems that combine microsensors for measuring electrical and physical biological parameters, electronics for sensor interface and signal processing, telemetry for wireless communication and powering, and micromachining for batch packaging.