SU-8 cantilever sensor system with integrated readout

We have developed a cantilever sensor array with integrated piezoresistive readout. The cantilevers are placed in a micro channel and the chip is fabricated in the epoxy-based photoresist SU-8. Surface stress changes on the cantilever due to molecular adsorption are detected by encapsulated Au piezoresistors. High sensitivity can be obtained due to the low Young's modulus of SU-8 and the piezoresistive readout will make the sensor compact to enable a portable device. This article describes the fabrication and characterisation of the cantilever sensor as well as some preliminary measurements using alkanethiols.