Date of Graduation
Honors Research Project
Bachelor of Science
Corrosion Engineering - Cooperative Education
Dr. Hongbo Cong
Dr. Ed Evans
Dr. Robert S. Lillard
In this work, we use electrochemical impedance spectroscopy (EIS) to observe the response of a single, photo-lithographically created, interdigital transducer (IDT) sensor, dimensions 6mm X 6 mm, with capacitive elements 70μm X 500 nm. The IDT was exposed to different wetting conditions, droplets of DI water, 0.1 M NaCl, and 0.6 M NaCl, in volumes of 0.1, 0.3, 1, and 5 μL. Deliquescence of solid NaCl salt particles in a dynamic-humidity (%RH Increasing, 33% to 85%) atmosphere is examined. Equivalent circuit fitting of impedance spectra suggests linear trends for the capacitive equivalent circuit element parameters and a decaying logarithmic trend for the resistive element, with respect to electrolyte concentration vs. area of wetting. The sensor development process includes a 1 by 5 proof-of-concept linear array, and the eventual goal of a 5 by 5 matrix array. The array sensor aims to (1) determine the overall fraction of wet surface area, and (2) distinguish between electrolytes of varying conductivity, in a 2-dimensional gradient across a surface.
Sutton, Nathaniel G.; Cong, Hongbo; Zhe, Jiang John; Li, Shengxi; and Zhu, Xiaoliang, "Multiplexed Sensor Array for Accurate Time-of-Wetness (TOW) Measurement" (2017). Honors Research Projects. 458.