| Title: | A Low-Power MEMS IDE Capacitor with Integrated Microhotplate: Application as Methanol Sensor using a Metal-Organic Framework Coating as Affinity Layer |
| Author(s): | Venkatesh MR; Sachdeva S; El Mansouri B; Wei J; Bossche A; Bosma D; de Smet L; Sudholter EJR; Zhang GQ; |
| Address: | "Beijing Research Centre, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands. m.ramachandrappavenkatesh@tudelft.nl. Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands. s.sachdeva.sumit@gmail.com. Department of Microelectronics, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands. B.ElMansouri@tudelft.nl. Department of Microelectronics, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands. J.Wei@tudelft.nl. Department of Microelectronics, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands. A.Bossche@tudelft.nl. Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands. d.bosma@tudelft.nl. Laboratory of Organic Chemistry, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands. louis.desmet@wur.nl. Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands. e.j.r.sudholter@tudelft.nl. Beijing Research Centre, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands. g.q.zhang@tudelft.nl. Department of Microelectronics, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands. g.q.zhang@tudelft.nl" |
| ISSN/ISBN: | 1424-8220 (Electronic) 1424-8220 (Linking) |
| Abstract: | "Capacitors made of interdigitated electrodes (IDEs) as a transducer platform for the sensing of volatile organic compounds (VOCs) have advantages due to their lower power operation and fabrication using standard micro-fabrication techniques. Integrating a micro-electromechanical system (MEMS), such as a microhotplate with IDE capacitor, further allows study of the temperature- dependent sensing response of VOCs. In this paper, the design, fabrication, and characterization of a low-power MEMS microhotplate with IDE capacitor to study the temperature-dependent sensing response to methanol using Zeolitic imidazolate framework (ZIF-8), a class of metal-organic framework (MOF), is presented. A Titanium nitride (TiN) microhotplate with aluminum IDEs suspended on a silicon nitride membrane is fabricated and characterized. The power consumption of the ZIF-8 MOF-coated device at an operating temperature of 50 composite function C is 4.5 mW and at 200 composite function C it is 26 mW. A calibration methodology for the effects of temperature of the isolation layer between the microhotplate electrodes and the capacitor IDEs is developed. The device coated with ZIF-8 MOF shows a response to methanol in the concentration range of 500 ppm to 7000 ppm. The detection limit of the sensor for methanol vapor at 20 composite function C is 100 ppm. In situ study of sensing properties of ZIF-8 MOF to methanol in the temperature range from 20 composite function C to 50 composite function C using the integrated microhotplate and IDE capacitor is presented. The kinetics of temperature-dependent adsorption and desorption of methanol by ZIF-8 MOF are fitted with double-exponential models. With the increase in temperature from 20 composite function C to 50 composite function C, the response time for sensing of methanol vapor concentration of 5000 ppm decreases by 28%, whereas the recovery time decreases by 70%" |
| Keywords: | Capacitor interdigitated electrodes MEMS microhotplate Zif-8; |
| Notes: | "PubMed-not-MEDLINEVenkatesh, Manjunath R Sachdeva, Sumit El Mansouri, Brahim Wei, Jia Bossche, Andre Bosma, Duco de Smet, Louis C P M Sudholter, Ernst J R Zhang, Guo Qi eng State Key Lab of Solid state lighting China/TU Delft-Beijing Research Centre/ Switzerland 2019/02/23 Sensors (Basel). 2019 Feb 20; 19(4):888. doi: 10.3390/s19040888" |
