- 标题
- 摘要
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Selective Gas Sensor Using Porous Silicon
摘要： The effect of polar and non-polar vapors, like ethanol, methanol, acetonitrile, chloroform and toluene vapors on porous silicon gas sensor was studied. We demonstrated that the selectivity of a single sensor can be achieved by the impedance measurements within the frequency range 103–105 Hz. It is shown that the capacitance of the structure and its frequency dispersion are different under influence of different gases providing an unique signature of an agent. A set of parameters is proposed in order to numerically characterize the response to different gases. The characteristic time of response to different vapors gives an additional parameter to sense gases selectively.
关键词： Organic Vapors,Gas Sensor,Porous Silicon,Selectivity
更新于2025-09-23 15:22:29
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Superfast, Porous and Organic Solvent Sensitive Actuator Based on EVOH Nanofibrous Membrane and PS Microspheres
摘要： Despite much progress in solvent-sensitive actuators, most of the actuators are sensitive to water, ethanol or acetone with low responsive speed and small curvature. Herein, a simple approach was introduced to fabricate a new solvent-sensitive bilayer actuator consisting of poly(vinyl alcohol-co-ethylene) (EVOH) nanofibrous membrane and polystyrene (PS) microspheres. The actuator showed superfast and multi-stimulus responsive ability to organic vapors of toluene, chloroform, THF and acetone. With solvents stimulation, the difference in swelling degree between the EVOH layer and PS microspheres layer contributed to the asymmetric expansions or contractions of two layers, therefore resulting in the mechanical deformation of the actuator. The flexible and porous EVOH nanofibrous membrane, as well as the spherical PS could improve the response rate and deformation scale. This bilayer actuator could bend quickly into a multi-coil with the curvature of 21.02 cm-1 within 0.15 s in response to toluene vapor, and the bending-unbending process could repeat more than 150 times when the deformation degree was controlled by cross-linking PS microspheres with divinylbenzene (DVB). This study will provide an important insight for the development of new solvent-sensitive devices and applications in volatile organic compounds detecting.
关键词： PS microspheres,EVOH nanofibrous membrane,multi-stimulus responsive,organic vapors,solvent-sensitive actuators
更新于2025-09-09 09:28:46