1-octadecanethiol Sam on CMOS-MEMS Gold-Plated Resonator via Dip-Cast for VOCS Sensing

We present a novel chemical VOCs sensor based on a CMOS-MEMS gold plated micro-resonator functionalized with a self-assembled monolayer (SAM) of 1- octadecanethiol (ODT) via solution-casting being, in contrast to common techniques, fully compatible with batch production without additional lithographic steps requirement. The device operated at 2-MHz being fully integrated with an on-chip Pierce oscillator circuit for self- sustained operation. The MEMS resonator was fabricated using a commercial 0.35-μm CMOS technology and coated through electroless nickel immersion gold (ENIG) process providing thiol-based extended functionalization compatibility over standard CMOS BEOL aluminum layers. This CMOS-MEMS sensor platform opens several possibilities to multiple functional SAMs-based organic surfaces by synthetizing functionalized thiols and build a sensing matrix for breath pattern recognition, depicting tremendous potential low-cost non-invasive disease diagnosis applications.