Microhotplate-Based High-Speed Polyimide Capacitive Humidity Sensors
Abstract:Polyimide thin films are locally cured on a sensor chip using MEMS microhotplates as an alternative solution to the conventional thermal curing and evaluated as high-speed humidity sensor materials. The polyimide locally cured at a temperature over 350 °C for 1 hour exhibits full imidization. There is no significant difference between the polyimide thin films cured in a conventional convection oven and those cured locally on MEMS microhotplates. The locally cured polyimide humidity sensors with a micro-bridge structure created using front-side etching with XeF2 gas show a sensitivity of 0.77 pF/%RH, a hysteresis of 0.61%RH, and a response time of 2.5 s. They also exhibit a low dielectric loss. In comparison, the sensors with a conventional structure exhibit a time response of 7 s. These results indicate that the locally cured polyimide films may be used as a dielectric material in high speed humidity sensors.
Document Type: Research Article
Publication date: 2009-08-01
More about this publication?
- The growing interest and activity in the field of sensor technologies requires a forum for rapid dissemination of important results: Sensor Letters is that forum. Sensor Letters offers scientists, engineers and medical experts timely, peer-reviewed research on sensor science and technology of the highest quality. Sensor Letters publish original rapid communications, full papers and timely state-of-the-art reviews encompassing the fundamental and applied research on sensor science and technology in all fields of science, engineering, and medicine. Highest priority will be given to short communications reporting important new scientific and technological findings.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites