Actuated Micro-Sensor for Magnetic Field Detection Based on Piezoresistor Transduction
Waddah Abdelbagi Talha1, Mohammed A. A. Emaleeh2, John Ojur Dennis3
1Waddah Abdelbagi Talha, Department of Electronic Engineering, University of Gazira Sudan, Wad Madani, (Sudan) North Africa.
2 Mohammed A. A. Emaleeh, Department of Control Engineering, University of Khartoum, (Sudan) North Africa.
3John Ojur Dennis, Departments of Electrical and Electronic Engineering, Universiti Teknologi Petronas, Perak, Malaysia.
Manuscript received on October 16, 2015. | Revised Manuscript received on October 27, 2015. | Manuscript published on November 05, 2015. | PP: 40-44 | Volume-5 Issue-5, November 2015 . | Retrieval Number: E2746115515/2015©BEIESP
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©The Authors. Published By: Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/
Abstract: One of the techniques used to measure the external magnetic field is by the transduction of the deflection produced by the Lorentz force into electrical signal using Piezoresistor technology. It is stated that the piezoresistive effect in silicon depends strongly on the crystal orientation, doping type, and concentration. In this paper the piezoresistive property of the Polysilicon is used as Piezoresistor transducer to study the transduction procedures. The results obtained observe the response of the different samples of piezoresistor transducer to transfer the deflection of the cantilever to electrical signal (voltage output). The sensitivity of the system is calculated for different samples at a fixed value of the applied force the percentage rate of change of the resistivity (ΔRp %) for different values of the cantilever deflections were obtained. It is observed that the change in resistance of the piezoresistor increases nonlinearly with the increase of the cantilever displacement. The Polysilicon Piezoresistor in Whetstone’s bridge configuration is used to transducer the response of the cantilever to electrical measurements at various voltages. Various dimensions of the cantilever were considered in the measurements. The highest sensitivity of the measurements (64mV/mT) is obtained for a thin beam of 0.6 µm polysilicon embedded in 2 µm thick silicon cantilever beam.
Keywords: Lorentz force; Polysilicon Piezoresistor; Bulk Micromachining; Wheatstone bridge.