We demonstrate a fiber-tip photoacoustic spectrometric sensor for trace gas detection. The sensor head is a miniature fiber-tip hollow-cavity with a deflectable polymer diaphragm. Periodic light absorption of gas molecules within the cavity generates an acoustic pressure wave, which causes deflection of the diaphragm. The hollow cavity also is a Fabry-Perot interferometer with which the diaphra...

A novel valveless micro impedance pump is proposed and analyzed in this study. The pump is constructed of a upper glass plate, two glass tubes, a PDMS (polydimethylsilxane) diaphragm with an electromagnetic actuating mechanism and a glass substrate. The actuating mechanism comprises an electroplated permanent magnet mounted on a flexible PDMS diaphragm and electroplated Cu coils located on a gl...

It 1s known that the deflection of a diaphragm 1s determmed by two mechamsms, bendmg moments or bendmg stress and tensile forces or membrane stress Usually the influence of tensile forces 1s not taken mto account when calculating the mechamcal properties of thm diaphragms Hence the mathematical descrlptlon thus obtamed will only be valid if the deflection of the diaphragm is small compared with...

This study presents an electromagnetically-actuated reciprocating pump for high-flow-rate microfluidic applications. The pump comprises four major components, namely a lower glass plate containing a copper microcoil, a middle PMMA plate incorporating a PDMS diaphragm with a surface-mounted magnet, upper PMMA channel plates, and a ball-type check valve located at the channel inlet. When an AC cu...

Abstract   In this paper analytical analysis of capacitive pressure sensor with clamped diaphragm is presented. Mechanical and electrical properties of the sensor are theoretically analyzed based on theory of thin plates with small deflection and the results are evaluated by use of finite element analysis. The central deflection and capacitance values under uniform external pressure are calcula...

A pressure sensor with a 200 μm diaphragm using silicon nanowires (SiNWs) as a piezoresistive sensing element is developed and optimized. The SiNWs are embedded in a multilayered diaphragm structure comprising silicon nitride (SiNx) and silicon oxide (SiO2). Optimizations were performed on both SiNWs and the diaphragm structure. The diaphragm with a 1.2 μm SiNx layer is considered to be an opti...

We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr₀.₅₂Ti₀.₄₈)O₃ (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initia...

In micro-satellites, delicate instruments are compacted into a limited space. This raises concerns of active cooling and remote cooling. Silicon based micro-pump arrays are employed thanks to manufacturing simplicity, a small cryogen charge, etc, and keep the instruments within a narrow cryogenic temperature range. The pumping capacity and reliability of the micro-pump are critical in terms of ...

Several models concemmg the senslhvlty of capaclhve pressure sensors have been presented m the past Modellmg of condenser nucrophones, which can be constdered to be a specml type of capacltlve pressure sensor, usually reqmres a more comphcated analysis of the senstttvlly, because they have a strong electnc field m the atr gap It IS found that tbe mechamcal sensltlvlty of condenser rmcrophones ~...

This article deals with effects of thermal stresses on stability and frequency response of a fully clamped circular microplate, which acts as the diaphragm of a capacitive MEMS microphone. Static and dynamic pull-in phenomena limit the stable regions of a capacitive MEMS microphone. The results show that the non-dimensional static pull-in voltage of the studied case is about 5.23 (38.6 V). On t...