Silicon micromachining in the fabrication of biosensors using living cells

A pH-sensitive silicon chip used to measure the metabolic rates of living cells trapped in a microvolume chamber is described. In addition, silicon micromachining can perform useful structural functions, such as the accurate definition of the microvolume chamber geometry and the etching of wells to entrap nonadherent cells. This silicon chip is part of an instrument called a microphysiometer which has a broad range of applications, such as in vitro toxicology, drug discovery, and testing for antiviral compounds.<>