A dielectrophoretic-gravity driven particle focusing technique for digital microfluidic systems

2015 ◽  
Vol 106 (20) ◽  
pp. 204101 ◽  
Author(s):  
Ehsan Samiei ◽  
Hojatollah Rezaei Nejad ◽  
Mina Hoorfar
Keyword(s):  
Microfluidic Systems ◽  
Particle Focusing ◽  
Gravity Driven ◽  
Digital Microfluidic

Gravity-driven hydrodynamic particle separation in digital microfluidic systems

RSC Advances ◽  
2015 ◽  
Vol 5 (45) ◽  
pp. 35966-35975 ◽  
Author(s):  
Hojatollah Rezaei Nejad ◽  
Ehsan Samiei ◽  
Ali Ahmadi ◽  
Mina Hoorfar
Keyword(s):  
Particle Separation ◽  
Separation Method ◽  
Electrode Configuration ◽  
Microfluidic Systems ◽  
Gravity Driven ◽  
Digital Microfluidic ◽  
Actuation Scheme

In the present study, the electrode configuration and actuation scheme are designed in a fashion to implement a gravity-based hydrodynamic particle separation method on digital microfluidic systems.

scholarly journals Split and flow: reconfigurable capillary connection for digital microfluidic devices

Lab on a Chip ◽  
2014 ◽  
Vol 14 (18) ◽  
pp. 3589-3593 ◽  
Author(s):  
Florian Lapierre ◽  
Maxime Harnois ◽  
Yannick Coffinier ◽  
Rabah Boukherroub ◽  
Vincent Thomy
Keyword(s):  
Microfluidic Devices ◽  
Microfluidic Systems ◽  
Digital Microfluidic

How to take advantage of superhydrophobic microgrids to address the problem of coupling continuous to digital microfluidic systems? A reconfigurable capillary connection for digital microfluidic devices is presented.

Numerical Multiphysics Modeling of Microdroplet Motion Dynamics in Digital Microfluidic Systems

2010 ◽  
Author(s):  
Ali Ahmadi ◽  
Jonathan F. Holzman ◽  
Homayoun Najjaran ◽  
Mina Hoorfar
Keyword(s):  
Numerical Algorithm ◽  
Moving Boundary ◽  
Microfluidic Systems ◽  
Multiphysics Modeling ◽  
Transient Motion ◽  
Proposed Model ◽  
Digital Microfluidic ◽  
Motion Dynamics

In this paper a novel numerical algorithm is proposed for modeling the transient motion of microdroplets in digital microfluidic systems. The new methodology combines the effects of the electrostatic and hydrodynamic pressures to calculate the actuating and opposing forces and the moving boundary of the microdroplet. The proposed model successfully predicts transient motion of the microdroplet in digital microfluidic systems, which is crucial in the design, control and fabrication of such devices. The results of such an analysis are in agreement with the expected trend.

Numerical Investigation of the Combined Effects of Biomolecular Adsorption and Microdroplet Evaporation on the Performance of the Electrocapillary-Based Digital Microfluidic Systems

2011 ◽  
Author(s):  
Ali Ahmadi ◽  
Mina Hoorfar
Keyword(s):  
Mass Loss ◽  
Protein Concentration ◽  
Adsorption Rate ◽  
Force Balance ◽  
Combined Effects ◽  
Microfluidic Systems ◽  
Gibbs Equation ◽  
Rate Effects ◽  
Digital Microfluidic ◽  
Force Balance Equation

In this article, microdroplet motion in the electrocapillary-based digital microfluidic systems is modeled accurately, and the combined effects of the biomolecular adsorption and micro-droplet evaporation on the performance of the device are investigated. An electrohydrodynamic approach is used to model the driving and resisting forces, and Fick’s law and Gibbs equation are used to calculate the microdroplet evaporation and adsorption rate. Effects of the adsorption and evaporation rates are then implemented into the microdroplet dynamics by adding new terms into the force balance equation. It is shown that mass loss due to the evaporation tends to increase the protein concentration, and on the other hand, the increased concentration due to the mass loss increases the biomolecular adsorption rate which has a reverse effect on the concentration. The modeling results indicate that evaporation and adsorption play crucial roles in the microdroplet dynamics.

scholarly journals Self-Cleaning: From Bio-Inspired Surface Modification to MEMS/Microfluidics System Integration

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 101 ◽  
Author(s):  
Di Sun ◽  
Karl Böhringer
Keyword(s):  
Surface Modification ◽  
System Integration ◽  
State Of The Art ◽  
Mechanical Systems ◽  
Surface Cleaning ◽  
Practical Application ◽  
Microfluidic Systems ◽  
Micro Electro Mechanical Systems ◽  
Self Cleaning ◽  
Digital Microfluidic

This review focuses on self-cleaning surfaces, from passive bio-inspired surface modification including superhydrophobic, superomniphobic, and superhydrophilic surfaces, to active micro-electro-mechanical systems (MEMS) and digital microfluidic systems. We describe models and designs for nature-inspired self-cleaning schemes as well as novel engineering approaches, and we discuss examples of how MEMS/microfluidic systems integrate with functional surfaces to dislodge dust or undesired liquid residues. Meanwhile, we also examine “waterless” surface cleaning systems including electrodynamic screens and gecko seta-inspired tapes. The paper summarizes the state of the art in self-cleaning surfaces, introduces available cleaning mechanisms, describes established fabrication processes and provides practical application examples.

Experimental Technique for Sensing Droplet Position in Digital Microfluidic Systems Using Capacitance Measurement

2010 ◽  
Author(s):  
Heather Martin ◽  
Miguel Murran ◽  
Rachael L’Orsa ◽  
Homayoun Najjaran
Keyword(s):  
Capacitance Measurement ◽  
Experimental Setup ◽  
Accurate Approximation ◽  
Microfluidic Systems ◽  
Effective Technique ◽  
Position Sensing ◽  
Capacitance Measurements ◽  
Manufacturing Procedure ◽  
Acquisition Device ◽  
Digital Microfluidic

Capacitance measurement has been identified as an effective technique for droplet position sensing in digital microfluidic systems mainly due to its non-intrusive nature. In essence, this technique relies on the correlation between the capacitance of two top-bottom electrodes with the amount of droplet overlap on the electrode. This paper describes an experimental setup used to gather capacitance data from a set of electrodes with varying droplet overlap to determine the droplet position. A prototype closed digital microfluidic (DMF) system consisting of an array of electrodes in the form of a 2 × 2 matrix was fabricated. A circular droplet was positioned on the DMF system, and capacitance measurements for each of the four electrodes were taken using a fast data acquisition device. A sufficiently accurate approximation of the droplet position was made using the four capacitance measurements. The paper presents the experimental results and also discusses the sources of error, viability of the experimental setup and manufacturing procedure for use in the development of capacitance measurement droplet position sensing techniques.

In situ characterization of microdroplet interfacial properties in digital microfluidic systems

Lab on a Chip ◽  
2010 ◽  
Vol 10 (11) ◽  
pp. 1429 ◽  
Author(s):  
Ali Ahmadi ◽  
Kurt D. Devlin ◽  
Homayoun Najjaran ◽  
Jonathan F. Holzman ◽  
Mina Hoorfar
Keyword(s):  
Interfacial Properties ◽  
Microfluidic Systems ◽  
In Situ Characterization ◽  
Digital Microfluidic
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