A Low-Power Instrumentation System for Nano-Electro-Mechanical-Sensors for Environmental and Healthcare Applications

This paper presents a low-power instrumentation system for cardiac infarction as well as for explosive detection applications using nano-electro-mechanical-cantilever sensors. The proposed circuit works on the principle of nano-meter deflection of cantilever sensors, because of the antigen-antibody interaction or the receptor-analyte vapor reactions over its surface. For the two different applications reported in this work, only the functionalization process of cantilever varies while the measurement circuit remains the same. The entire instrumentation hardware consumes less than 2 mA current (bio-marker detection) while measuring resistance changes down to 14 parts per million (ppm). The measured results using this battery operated system have been presented along with a calibration technique. The size of this LCD (Liquid crystal display) based system was reduced to fit into a hand held point-of-care form factor. In addition, users can operate this measurement system with the help of a computer and analyze the data in labview graphical user interface (GUI). This demonstrates the possible application for detection of myocardial infarction in clinical settings and explosives at airports.