A wireless chemical and biological microsensor based on dissolvable membranes

We demonstrate a wireless bio/chemical microsensor based on dissolvable membranes. The dissolution of a target specific membrane enables fluid flow into an on-chip microcapacitor, thereby drastically changing its impedance. Here, this fact is used to generate large intrinsic amplification and thus, a large output voltage, which allows the microsensor to directly drive a microcontroller operating at 3.6964 MHz, without complex electronics. The electronic modules, operating at 5 V, have been integrated onto a printed circuit board of dimension 10.2 cm times 10.2 cm, consuming 135 mW of power. An automated procedure to estimate the concentration of the sensed species (here, dithiothreitol) and interface circuitry for wireless transmission at 916.48 MHz with a range of 150 ft in closed premises are realized