Interdigitated humidity sensors for a portable clinical microsystem

Abstract

This paper presents and compares two capacitive humidity sensors with interdigitated electrodes for a portable clinical application. A polyimide-sensitive layer covers the first structures and the optimized ones include a benzocyclobutene-sensitive layer and a heating resistor. Humidity measurements results are presented, in particular sensors response time in absorption, which are very small (inferior to 500 ms). Next, mechanisms of absorption and adsorption in a polymer layer are described and the two structures are compared. Suitability of optimized sensors for our application is discussed: new structures allow us to increase sensitivity and decrease response time. When the structure is maintained at 40 degrees C by its heater, the response time is 200 ms and the total desorption time is 11 s.

Compliant and low-cost humidity nanosensors using nanoporous polymer membranes

“…In addition, the brittleness makes ceramics not suitable for certain applications such as in situ water leakage detection on roofs where people can walk on top of them. Another common sensor material, 0925 polyimide film with roughened surface, has been widely used [11][12][13][14][15][16][17]. But it swells with water absorption and has a relatively lower sensitivity.…”

Determination of Sugar Content in Sugar Solutions using Interdigital Capacitor Sensor

“…The interdigital sensors have been used for estimation of properties of dielectric material for dairy products [23], humidity and gas sensors [24], biosensor applications [25]- [28], and detection of dangerous toxins in contaminated seafood [29]. The applications of these sensors depend on both the characteristic of the particular sensor chosen and also on the characteristic of the material under test (MUT).…”

A Simple Capacitive Sensor Array Based on a Metal-Insulator-Metal Structure

“…Capacitive detection method is a widely used technique to measure relative humidity(RH) [1][2][3][4][5][6][7][8]. Generally, capacitive humidity sensors are comprised of a pair of electrodes and a humidity-sensitive insulating layer, made from materials such as polymer [9][10][11][12], metal oxide [13,14], and semiconductors [15,16].…”