Piezoresistive cantilever array for chemical and biological detection

We have developed a miniature sensor platform based on a piezoresistive microcantilever array that has extremely high detection sensitivity. The piezoresistive cantilevers are designed such that they can be operated in air or under liquid. A common mode rejection technique has yielded a rugged sensor that is immune to vibrations and other parasitic deflections. We demonstrate that these cantilever sensors can be used to detect real-time DNA hybridization. The same cantilever platform is used to detect plastic explosive vapor of hexahydro-1,3,5-triazine (RDX) at parts-per-trillion (ppt) levels within few seconds of exposure. This micro electro mechanical system (MEMS) sensor design allows for the incorporation of more cantilever elements without increasing the overall size of the chip for achieving pattern recognition when each cantilever is coated with a different chemically selective layer.