MEMS Handbook

Hasson

et al. 2016

J. Sens. Sens. Syst.

Abstract. Measuring air pressure using a capacitive pressure sensor is a robust and precise technique. In addition, a system that employs such transducers lies within the low power consumption applications such as wireless sensor nodes. In this article a high sensitivity with an elliptical diaphragm capacitive pressure sensor is proposed. This design was compared with a circular diaphragm in terms of thermal stresses and pressure and temperature sensitivity. The proposed sensor is targeted for tyre pressure monitoring system application. Altering the overlapping area between the capacitor plates by decreasing the effective capacitance area to improve the overall sensitivity of the sensor ( C/C), temperature sensitivity, and built-up stresses is also examined in this article. Theoretical analysis and finite element analysis (FEA) were employed to study pressure and temperature effects on the behaviour of the proposed capacitive pressure sensor. A MEMS (micro electro-mechanical systems) manufacturing processing plan for the proposed capacitive sensor is presented. An extra-low power short-range wireless read-out circuit suited for energy harvesting purposes is presented in this article. The developed read-out circuitry was tested in terms of sensitivity and transmission range.

Section: Capacitive Pressure Sensorsmentioning

confidence: 99%

Section: Capacitive Pressure Sensorsmentioning

confidence: 99%

Section: Piezoresistive Pressure Sensorsmentioning

confidence: 99%

See 1 more Smart Citation

A micro-capacitive pressure sensor design and modelling

Hasson

et al. 2016

J. Sens. Sens. Syst.

“…Under such conditions, by using long-wave approximation and simplifying continuity and momentum equations for slow ow of Newtonian incompressible viscous uid, one achieves a single equation governing lm evolution. For the simplest case in which the lm is supported from below by a solid surface and is subjected to constant surface tension forces and gravity is the only body force, the evolution of thin lms is expressed by a single fourth order equation [1]. When the liquid lm is positioned under a plate, except for small Bond numbers (relatively large surface tension force to gravitational one), the lm is unstable and Rayleigh-Taylor instability occurs [2].…”

Section: Introductionmentioning

confidence: 99%

Evolution of Thin Liquid Film for Newtonian and Power-Law Non-Newtonian Fluids

Nasehi

Shirani²

2017

Scientia Iranica

Abstract. Analytical relations for slow-motion thin liquid lms bounded by a xed wall and free surface for Newtonian and non-Newtonian uids are obtained in this work. Assuming long-wave approximation, the momentum and continuity equations for thin liquid lms of power-law uids are simpli ed and solved analytically to derive the evolution equation of thin liquid lms. The evolution equation is derived for two-and threedimensional cases. A relation for evolution of thin lms is obtained for a simple case in which the liquid lm is supported from below by a solid surface and subjected to gravity and constant surface tension forces. This evolution equation of thin lm has been solved numerically in order to compare the behavior of Newtonian and non-Newtonian liquids for di erent Bond numbers. It is shown that the power-law model at low and high strain rates is invalid and it a ects the results. The Rayleigh-Taylor instability is another subject that is studied in this work. This interesting phenomenon is investigated by numerically solving the evolution equation for di erent Bond numbers. The results show that the evolution of the free surface thin lm for pseudo plastic uids is di erent from that for Newtonian and dilatant uids.

International Journal of Advanced Robotic Systems

“…[1][2][3][4][5][6][7]. Micropositioning is the ability to move objects with a micrometric resolution by a defined stroke [8]. A controlled microactuator is needed to carry out these tasks.…”

Section: Introductionmentioning

confidence: 99%

Design and Analysis of a Fibre-Shaped Micro-Actuator for Robotic Gripping

Borboni

Aggogeri

Faglia

2013

A prototype of an automatic micropositioning system was developed. This prototype uses a shape memory alloy (SMA) actuator, a dedicated PI controller and a piece of software to command a desired motion profile for the actuator. The proposed micropositioning system is characterized by a 4 mm stroke, a 1 μm resolution and a 70 g nominal force and can be commanded directly from a personal computer and without human retroaction. The closed loop positioning resolution (1 μm) is obtained in spite of inaccurate system behaviour during its movement.