Fabrication of micro-mechanical sensors with the polymer SU-8

In English In this paper, we present the design and fabrication of biosensors based on SU-8 cantilevers with a thickness ≤ 5μm. The processing of the polymer was optimized to reduce initial bending of the devices which is essential for optical read-out of the cantilever deflection. Solvent absorption in the SU-8 had to be minimized to reduce drift of the cantilever bending during measurements in liquid. The shelf-life of the sensors was improved to enable storage for several months. Further, we introduced methods for process integrated metallization, backside passivation and surface functionalization allowing the fabrication of a variety of cantilever-based sensors.