Configurable electrodes for capacitive-type sensors and chemical sensors

Kummer, A.; Hierlemann, Andreas

doi:10.1109/jsen.2005.856547

Cited by 29 publications

(23 citation statements)

References 37 publications

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“…Representative examples of such polymers that became “classic” benchmark sensing materials against which numerous other new materials have been compared are presented in Figure 11. One of these polymers, polyetherurethane (PEUT, Figure 11a), 86 served as a coating on a capacitance transducer in a passive RFID sensor (Figure 5c) and was used to demonstrate detection of volatile organic compounds and water vapor as shown in Figure 12a. Two variable parameters that modulated the capacitance of the sensor were changes in the dielectric constant and swelling of sensing film.…”

Section: Integration Of Sensing Materials With Transducersmentioning

confidence: 99%

Materials and Transducers Toward Selective Wireless Gas Sensing

et al. 2011

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Introduction 7315 1.1. Diversity of Monitoring Needs of Volatiles 7315 1.2. Chemical Interferences As the Key Noise Parameter for Wireless Sensors 7316 1.3. Goals and Scope of This Review 7317 1.4. Topics That Are Out of Scope of This Review 7317 2. Anatomy of Wireless Gas Sensors 7317 2.1. Active and Passive Wireless Sensors 7318 2.2. Transducers for Wireless Passive Sensors 7319 2.3. RFID Sensors 7320 2.4. Key Performance Factors of Wireless Sensors 7320 2.5. Summary of Specific Requirements for Wireless Gas Sensors 7321 3. Need for Transducers with Multiple Response Mechanisms 7321 3.1. Limitations of Sensor Arrays for Tethered and Wireless Gas Sensing 7322 3.2. Data Processing 7322 3.3. Multivariate Sensing 7323 4. Integration of Sensing Materials with Transducers 7323 6.3. System Approach for Development of Wireless Gas Sensors 7345 6.4. Path Forward 7345 Author Information 7346 Biographies 7346 Acknowledgment 7347 References 7347

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Section: Integration Of Sensing Materials With Transducersmentioning

confidence: 99%

Materials and Transducers Toward Selective Wireless Gas Sensing

et al. 2011

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“…Reducing the electrode periodicity (width spacing) increases sensitivity (IDE-B versus IDE-C, same planar area). Simulations on IDE structures show that % of the electric field is contained in a distance perpendicular to the substrate surface equal to half the electrode periodicity [8]. Thus, an IDE with 6 m periodicity (IDE-C) will better confine the electric field within the 1.5-m-thick GLAD film, as compared with an IDE with 8 m periodicity (IDE-B).…”

Section: B Sensor Characterizationmentioning

confidence: 99%

Capacitive Humidity Sensors With High Sensitivity and Subsecond Response Times

2007

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Capacitive-based humidity sensors were fabricated using coplanar interdigitated electrodes coated with nanostructured TiO 2 thin films produced by glancing angle deposition. In this letter, we show that increased sensitivity (nF/%RH) is obtained by decreasing the electrode periodicity or by increasing the planar area of the electrodes, or both. The devices were sensitive over a wide range of relative humidity levels ( 1% to 92%) and exhibited extremely fast, subsecond response times. Typical adsorption and desorption response times were measured to be 220 and 400 ms, respectively.

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“…If the dielectric constant of the polymer is lower than that of the analyte, the capacitance will be increased, and, if the polymer dielectric constant is larger than that of the analyte, the capacitance will be decreased. This effect has been previously detailed and supported by simulations [36][37][38]. For thick polymer layers the sensitivity, S, is the change in capacitance, C, in dependence of the change in the analyte concentration, c A , as given by:…”

Section: Capacitive Sensor Array and Readout Circuitrymentioning

confidence: 73%

“…This is due to the increased polymer/analyte volume within the field line region exhibiting a larger dielectric constant than that of the substituted air [36,37]. Thin polymer layers include layer thicknesses of less than half the periodicity of the electrodes.…”

Section: Capacitive Sensor Array and Readout Circuitrymentioning

confidence: 99%