Hybrid Micro Electro Mechanical Sensor based onGraphene Oxide/Polyvinyl Alcohol for Humidity Measurements

• Main Authors: Carlo Trigona, Ammar Al-Hamry, Olfa Kanoun, Salvatore Baglio
• Format: Article
• Language: English
• Published: MDPI AG 2018-12-01
• Series: Proceedings
• Subjects: redundant measurements; hybrid sensor; nanomaterial; GO/PVA composite; humidity sensor; micromachined sensor
• Online Access: https://www.mdpi.com/2504-3900/2/13/1011

In this paper, we present a redundant micromachined sensor based on Bulk and Etch. <b>Silicon-on-Insulator </b>(BESOI) process for measurements of relative humidity (RH) by using Graphene-Oxide/Polyvinyl-Alcohol (GO/PVA) composite. The microsensor is a mechanical oscillator composed of a proof mass with multilayer of nanomaterials (GO/PVA) and suspended by four crab leg springs. The realized redundant approach concerns the possibility to use different readout strategies in order to estimate the same measurand: RH. This is an intriguing solution to realize a “robust measurement system”, with multiple outputs by using the GO/PVA as functional material. In presence of RH variation: (1) it changes its mass and; as consequence; a variation of the natural frequency of the oscillator can be observed in the frequency domain; (2) it also varies the conductivity which can be measured by using two integrated electrodes. The sensor has been designed; studied; modeled and experimental results demonstrate the effectiveness of our implementation.