scispace - formally typeset
Search or ask a question
Author

D. Mary Sugantharathnam

Bio: D. Mary Sugantharathnam is an academic researcher from Government College. The author has contributed to research in topics: Curvelet & Cantilever. The author has an hindex of 1, co-authored 2 publications receiving 8 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the authors have initially fabricated the MEMS mechanical switch with molybdenum cantilever beam using surface micromachining technique, however, the yield is poor.
Abstract: This paper illustrates the methodology adopted for the molybdenum cantilever beam fabrication and the issues faced in the successful realization of such a beam which would be essential component of the PWM based MEMS pressure sensor. The authors in this work have initially fabricated the MEMS mechanical switch with molybdenum cantilever beam using surface micromachining technique. The molybdenum beam switch has been successfully implemented with the proposed fabrication process. However, the yield is poor. The issue regarding the poor yield has been discussed and methods to overcome the same for the enhancement of yield have been presented.

9 citations

Journal ArticleDOI
TL;DR: A novel approach for accomplishing Poisson noise removal in biomedical images by multiresolution representation where Fast Discrete Curvelet Transform is integrated with Rudin–Osher–Fatemi (ROF) model based on VST.
Abstract: This paper introduces a novel approach for accomplishing Poisson noise removal in biomedical images by multiresolution representation. Methods of denoising are described based on three classical methods: (1) Fast Discrete Curvelet Transform (FDCT) with simple soft thresholding, (2) Variance Stabilizing Transform (VST) combined with FDCT where hypothesis tests are made to detect the significant coefficients and (3) The proposed method where the FDCT is integrated with Rudin–Osher–Fatemi (ROF) model. Much of the literature has focused on developing algorithms for the removal of Gaussian noise where the estimation is often done by finding a Curvelet and by thresholding the noisy coefficients. However not much has been done to remove Poisson noise in biomedical images. But in most of the medical images, the recorded data are not modeled by Gaussian noise but is the realization of Poisson process. Hence, in this work, FDCT integrated with ROF model based on VST is proposed. The VST is applied so that the transformed data are homoscedastic and Gaussian. A classical hypothesis testing framework is used to detect the significant coefficients and an iterative scheme is used to reconstruct the final estimate. A central difference total variation term in the discrete ROF model is used. The model is experimented on a large number of clinical images like Computed Tomography (CT) images, X-Ray images, Positron Emission Tomography (PET) images and Single Photon Emission Computed Tomography (SPECT) images and the performances are evaluated in terms of Peak Signal to Noise Ratio (PSNR) and the Universal Quality Index (UQI). The results are compared with those obtained by the other two existing algorithms proposed in the literature. Numerical results show that the proposed algorithm obtains higher PSNR and UQI than the other two methods.

1 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: Experimental results show that the cantilever-structured sensor samples have significantly higher sensitivity compared to those with the PDMS dielectric layer.
Abstract: It is common in the field of printed electronics that polydimethylsiloxane (PDMS) be used as a dielectric layer for capacitive sensors because of its high elasticity and restoration force. However, capacitive sensors with the PDMS dielectric layer have a lower sensitivity than those with an air-gap structure that has been fabricated by the conventional micro-electromechanical system (MEMS) process. This paper presents a productive method for fabricating air-gap structures for touch sensors by roll-to-roll slot-die coating. The air-gap is formed by coating and removing a sacrificial layer. Cantilever-structured capacitive touch sensors with an air-gap are fabricated as follows: First, the bottom electrode, the dielectric layer, and the poly(vinyl alcohol) (PVA) sacrificial layer are roll-to-roll slot-die-coated on a flexible substrate. In addition, the spacer layer is spin-coated. On the sacrificial and spacer layers, the top electrode and structural layer are formed by spin-coating. Then, the air-gap and cantilever structure are made by removing the sacrificial layer in water. The cantilever-structured sensor samples are examined in terms of sensitivity, hysteresis, and repeatability. In particular, the electrical performance of the samples is compared to those with the PDMS dielectric layer. Experimental results show that the cantilever-structured sensor samples have significantly higher sensitivity compared to those with the PDMS dielectric layer.

12 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of a single surface crack on the static deflection and natural frequency of an electrostatically actuated micro-beam are formulated and compared for use in an analytical model and numerical simulations.

10 citations

Journal ArticleDOI
TL;DR: The paper concludes that the piezoelectric material, piezOElectric layer thickness, and silicon membrane thickness are the most three-factors influence the PMPH performances at low vibration levels and extremely low frequency about 1.2 Hz.

9 citations

Journal ArticleDOI
04 Jul 2020-Sensors
TL;DR: This paper presents the fabrication by means of roll-to-roll slot-die coating and characterization of air gap-based cantilever type capacitive acceleration sensors, designed to have a six layers structure with an air gap.
Abstract: This paper presents the fabrication by means of roll-to-roll slot-die coating and characterization of air gap-based cantilever type capacitive acceleration sensors As the mass of the sensor moves in the opposite direction of the acceleration, a capacitance change occurs The sensor is designed to have a six layers structure with an air gap Fabrication of the air gap and cantilever was enabled by coating and removing water-soluble PVA The bottom electrode, the dielectric layer, and the sacrificial layer were formed using the roll-to-roll slot-die coating technique The spacer, the top electrode, and the structural layer were formed by spin coating Several kinds of experiments were conducted for characterization of the fabricated sensor samples Experimental results show that accelerations of up to 36 g can be sensed with an average sensitivity of 000856 %/g

7 citations

Journal ArticleDOI
TL;DR: In this article, the authors presented the design and simulation of a pressure sensor integrated with two identical hall effect sensors and permanent magnets arranged in a differential configuration for measuring pressure in the range of 0-20 bar.
Abstract: This paper presents the design and simulation of a pressure sensor integrated with two identical hall effect sensors and permanent magnets arranged in a differential configuration for measuring pressure in the range of 0–20 bar. The sensor uses the deflection of a circular diaphragm with a simple rigid mechanical structure to convert the applied pressure to a differential hall voltage output. A complete analytical modelling was carried out by assuming the rigid mechanical structure as a central circular boss structure on the circular diaphragm. Numerical simulations were also carried out in COMSOL Multiphysics FEM tool to support the analytical results. Before going for actual fabrication, the optimum sensor dimensions were also fixed from both analytical modelling and numerical simulation analysis. The sensor was planned to be fabricated completely using different grades of stainless steel and hence can be used in high temperature and corrosive environments. The fabricated sensor can be of low cost, self-packaged and the differential arrangement helps in compensating for any ambient temperature variations.

7 citations