Polymeric mechanical sensors with piezoresistive readout integrated in a microfluidic system

Micrometer sized cantilevers can be used as highly sensitive bio/chemical sensors and are usually fabricated in silicon. Here, we demonstrate the integration of an array of polymeric cantilever sensors into a microfluidic system designed for bio/chemical detection. The cantilever-sensors as well as the microfluidic system are fabricated in the polymer SU-8. Gold strain gauge resistors are incorporated in the cantilevers in order to make them sensitive to changes in surface stress. The cantilever device is fabricated as two separate parts, which are subsequently bonded together using SU-8 as glue. The sensitivity and noise response of the polymeric cantilevers are measured. The measured noise level indicates that the device is suitable for molecular recognition measurements.