Sensing and quantifying ions in liquid is important in many research and commercial applications. For instance, pH is often a key component in manufacturing. In biology, sensing ions in solution, such as lab-on-a-chip applications, can be pivotal to an effective application. In many of these technology areas, miniaturization and low cost production of ion sensors is critical.To address this challenge, investigators at University of California at Berkeley have developed a MEMS nanowire ion sensor. This sensor employs a MEMS device where ions are sensed with nanowires using an alternating current (AC) electric field. The MEMS nanowire ion sensor can serve as a chemical sensor. By example, the MEMS nanowire ion sensor can be employed as a pH sensor or pH monitor for environment, infrastructure or plant facility. In biologic applications, the MEMS nanowire ion sensor can serve as a biosensor for biomolecule detection, DNA sequences, blood testing, and an ion species identifier, among others.