Experimental investigations are performed to determine the influence of electrical excitation and geometrical parameters on the performance of piezoelectric valveless micropumps fabricated on printed circuit board substrates. Strain gauges and shunt resistor are used in conjunction with a data acquisition system to form an effective transducer, capable of providing magnitude and phase response information pertaining to fluid-structure interaction. Effect of conical diffuser geometry on the displacement response and pressure flow characteristics are studied. With suitable variations in the design of the diffuser element and input excitation parameters, the ability of the valveless micropump can be extended to include forward, reversed and bidirectional flow features. The characteristic signatures of single and two peaks in flowrate or pressure data are captured in the displacement phase response. System identification approach is proposed to model and predict the performance of valveless micropumps. © Springer-Verlag 2011.

Dhiman Chatterjee

Department of Mechanical Engineering

BI-DIRECTIONAL FLOWS

Characteristic signature

Conical diffuser

Data acquisition system

DIFFUSER ELEMENTS

DISPLACEMENT PHASE

Displacement response

Electrical excitation

Excitation parameters

Experimental investigations

Geometrical parameters

PARAMETRIC CHARACTERIZATION

Phase response

PRESSURE DATA

PRESSURE-FLOW CHARACTERISTICS

SHUNT RESISTORS

System identifications

VALVELESS MICROPUMPS

geometry

Piezoelectricity

Printed circuit boards

Pumps

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Microsystem Technologies

In this paper, performance of piezoelectrically actuated pyramidal valveless micropumps is studied experimentally in detail. Valveless micropumps based on silicon and glass substrate are fabricated using MEMS technology. Two different sizes of micropumps having overall dimensions of 5 mm × 5 mm × 1 mm and 10 mm × 10 mm × 1 mm are fabricated and characterized. In the fabricated micropumps, the thickness of silicon diaphragm is <20 µm which gives the advantage of operating pump at low voltage with excellent stability and consistency. The performance of micropumps in terms of flowrate and backpressure is evaluated for a wide range of driving frequency and actuating voltages. The maximum flowrate of water in the 10-mm micropump is 355 µl/min and backpressure of 3.1 kPa at zero flowrate for an applied voltage of 80 V at frequency 1.05 kHz. The reported micropumps have low footprint, high flowrate and backpressure. Thus, these micropumps are especially suited for biological applications as these can withstand adequate amount of backpressure. Comparative study of the performance of these micropumps with those available in the literature brings out the efficacy of these micropumps. © 2016, Springer-Verlag Berlin Heidelberg.

Microfluidics and Nanofluidics

Experimental characterization of piezoelectrically actuated micromachined silicon valveless micropump

Micropumps form the heart of several microfluidic systems like micro total analysis system (µTAS) and drug delivery devices, which have resulted from the advancement of silicon micromachining technology. Among the different available types of micropumps, valveless micropumps are better suited for biological applications as they do not have flow-rectifying valves and are less prone to clogging and wear. However, their main drawback is low thermodynamic efficiency. This can be improved if we have a better understanding of the effects of geometry on the performance. This forms one of the objectives of this work. This chapter describes the activity on the design and development of valveless micropumps. A numerical parametric study of the performance of valveless micropumps has been carried out and is presented to bring out the effects of different geometrical parameters. Based on these design approaches, silicon-based micropumps are fabricated and characterized. The performance of one of these micropumps is compared with designed value in this work. © 2014 Springer India.

Springer Tracts in Mechanical Engineering

Design and development of a piezoelectrically actuated micropump for drug delivery application

Numerical characterization of valveless micropumps involves fluid-structure interaction (FSI) between a membrane and the working fluid. FSI being computationally difficult, efforts have been mainly restricted to analyzing a given micropump performance. Designing an optimum micropump involves understanding the role of different geometric parameters and this forms the focus of the present work. It is shown that membrane displacement information extracted from a two-way coupled FSI simulation at a given frequency can be reliably used to carry out fluid flow simulations over a wide range of geometrical and operating parameters. The maximum variation between this approach and FSI is within 4% while there is a drastic reduction in computational time and resource. A micropump structure suitable for MEMS technology is considered in this work. An optimum micropump geometry, having a pump chamber height of 50μm, diffuser length of 280μm, throat width of 100μm and separation distance between nozzle and diffuser openings of 2.5mm, is recommended. The numerical prediction of flowrate at 200Hz (68μlmin 1) for this pyramidal valveless micropump matches well with the experimental data (60μlmin 1) of the micropump fabricated using MEMS-based silicon micromachining. Thus an efficient numerical method to design valveless micropumps is proposed and validated through rigorous characterization. © 2012 IOP Publishing Ltd.

Smart Materials and Structures

An efficient numerical method for predicting the performance of valveless micropump

Parametric characterization of piezoelectric valveless micropump

With constraints on size, cost, reliability, and performance for liquid-based cooling systems, the design of modular micropumps suitable for an integrated thermal management system still remains a challenge. In this paper, the effectiveness of a low-cost valveless micropump-heat exchanger on a printed circuit board is investigated for electronic cooling. Signal conditioning and control electronics are integrated with the fluidic components on the substrate to form a compact modular unit. Piezoelectric actuation and conical diffusers are utilized to generate pulsating flow through a minichannel heat sink. With ethanol as the working fluid, the tested pump reached a maximum flowrate and a pressure head of 2.4 ml/min and 743 Pa at an input voltage of 6 VDC. Suitability of the system for active real-time temperature control has been demonstrated at two input heater power levels of 1.45 and 2.5W A maximum reduction of 57 per cent in the average heat sink surface temperature could be achieved at a maximum power consumption of 150 mW by the micropump. © IMechE 2009.

Fulltext

Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science

Design and development of a modular valveless micropump on a printed circuit board for integrated electronic cooling

Journal of Sound and Vibration

Modeling and study of dynamic performance of a valveless micropump

Steady and unsteady flow analysis in microdiffusers and micropumps: a critical review

International Journal of Heat and Mass Transfer

Loss characteristics and flow rectification property of diffuser valves for micropump applications

Journal	Microsystem Technologies
ISSN	09467076
Open Access	No