Many infrastructure challenges of national interest such as building integrity need new technology breakthroughs on the small ubiquitous sensors, operated in the passive radio-frequency identification (RFID) manner. This technology will cause great impact to embedded biomedical sensors as well. We propose such a microsystem that is composed of a broadband directional antenna and a nonlinear transmission line (NLTL) with application-specific sensing capacitors as the segment varactors. External inquisitive signal is received by the antenna and travels forth and back on NLTL with harmonic generation and phase-shift coding by the sensing capacitors. The output signal is transmitted in the harmonic frequency to avoid self jamming in the current RFID technology, which can significantly increase the bit rate of this miniaturized passive system. Two model systems with foot prints less than 20mm will be demonstrated: an acidity sensor for structural health monitoring and an embedded sensor for intra-ocular pressure (IOP) on hard contact lens. The design of the micro sensor system will be used as a lower-level undergraduate curriculum module to show that engineering directly touches people?s life. The misconception of society irrelevance of engineering has turned away many brilliant female and minority students from physical electronics careers.
