Browsing by Author "Dao, DV"

Now showing 1 - 4 of 4

item: Conference-Full-text
An Artificial Appendage for Swimming Microrobots in Non-Newtonian Fluids
(IEEE, 2021-07) Perera, KNM; Amarasinghe, YWR; Dao, DV; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Micron-scale mobile robots are being widely used in bioengineering applications, such as in a lab-on-a-chip (LOC) device, due to their capabilities of manipulation, sensing and transportation. Shear rate dependency of rheological properties of a non-Newtonian fluid enables swimming using geometrically reciprocal motion for a microswimmer. Therefore, it is not mandatory to use propulsive mechanisms that are slender in nature such as artificial flagella or cilia to generate non-reciprocal motion. We propose a design approach based on numerical simulations to select a suitable artificial appendage geometry to be used as a propulsion mechanism for a mobile microrobot. Here, the artificial appendage is considered to undergo rowing motion to generate propulsion. The fluid-structure interaction is computed numerically and three criteria are considered for the selection. In this study, a rectangular and a circular geometry are compared highlighting the proposed approach. The circular geometry showed better capability in terms of propulsion force generation, making it more suitable as a propulsion mechanism.
item: Conference-Full-text
Design and simulation of mems based 5-dof tactile force sensor
(IEEE, 2016-04) Udayanga, TDI; Jayathilaka, WADM; Amarasinghe, YWR; Dao, DV; Jayasekara, AGBP; Bandara, HMND; Amarasinghe, YWR
This paper describes design and simulation of five degrees of freedom (5-DOF) Micro-Electro-Mechanical systems (MEMS) based tactile force sensor. Tactile sensing involves with measuring physical parameters such as force, temperature, etc. with the aid of physical touch. Over the past decades tactile sensors are gaining popularity over non-contact sensors in biomedical and robotic applications. Proposed sensor design with 3mm x 3mm x 300μm dimensions, has the capability to measure not only the magnitude but also the direction of the force applied. A wagon wheel spring structure was proposed, where 8 beams work as springs to relief the force applied. Behavior of these 8 beams are monitored under each loading conditions using defused piezoresistive sensing elements. A finite element analysis of structure was performed to optimize and validate the structure and Multiphysics analysis was performed to validate the working principal of the proposed sensor.
item: Conference-Full-text
Design and simulation of mems based piezoresitive pressure sensor for microfluidic applications
(IEEE, 2018-05) Munas, FR; Amarasinghe, YWR; Kumarage, P; Dau, VT; Dao, DV; Chathuranga, D
This paper presents the design and simulation of MEMS based piezoresistive pressure sensor for microfluidic applications. Geometrical parameters are very much considerable when designing microstructure of the pressure sensor. Hence, an analysis is carried out by changing the dimensional parameters of three different diaphragm geometries namely square shaped diaphragm, circular shaped diaphragm and cross sectional beam shaped diaphragm respectively. This is performed in three dimensional mesh plots using Matlab. The Finite Element Method (FEM) analyses are performed in COMSOL and by comparing the results, the square type diaphragm is chosen as best diaphragm geometry for the microfluidic applications. In addition, modal analysis is carried out by using Ansys to identify the natural frequency of the best diaphragm geometry. Also Piezoresistive sensing elements are designed and simulated by performing coupled field analysis using COMSOL Multiphysics. Simulation results reveal that piezo resistive square type pressure sensors have high sensitivity in a wide range of pressures.
item: Article-Abstract
Development of a quantum tunneling composite based 1-DOF tactile sensor
Udayanga, TDI; Fernando, DAMR; Chaturanga, HLPL; Amarasinghe, YWR; Dao, DV
Tactile Sensing is the measure of tactile parameters such as pressure, force, temperature, vibration, etc. by sense of touch. This paper presents the development of a novel one degree of Freedom (DOF) tactile sensor which can be used to measure the force applied at one direction. A novel composite material named as Quantum Tunneling Composite (QTCTM) is used as the sensing element for the developed sensor. The sensor structure consists of a spring load mechanism to increase the sensing range of the QTCTM. Thanks to the improved characteristics and cost effectiveness the sensor application in industry is promising.