Design of Microfluidic Device and Measurements of MPWM for Single Cell /Particle Manipulation

Abstract

A microfluidic device designated for measurement of fluidic flows with different viscosity, necessary within trapping/realising of cells/particles system has been developed. We use a new concept as Microfluidic Pulse Width Modulation (MPWM) for controlling transport of a single cell/particle. The image processing helped the nano-hydraulic volumes/flow rates measurement, through tracking inovative methods with the purpose to build a flow sensor. The device open an unique opportunitie for single cell study with applications in biomedical devices, tools for biochemistry or analytical systems.

Novel PDMS-Based Sensor System for MPWM Measurements of Picoliter Volumes in Microfluidic Devices

“…Based on a concept from the electrical engineering field, the MPWM system controls the transport of fluids through the microfluidic channels. Ardeleanu et al [56] used MPWM to measure volumes/flow rates for future application in cell/particle trapping and release. Ainla et al [59] used pulse width modulation (PWM) for microfluidic diluter and Unger et al used PWM for dynamic duty cycle over time for liquid flows [60].…”

“…For precise flow control, many methods including optical volumes and flow rates measurements were developed [56,58]. An optical volumetric measurement technique has been developed to enhance the measurement in the picoliters region.…”

“…For this reason, we used a microchannel with 120 µm in diameter, and a good magnification to have a clear image of the boundary between two immiscible fluids like air-liquid and/or liquid 1 -liquid 2 . The computerized generator of absolute coordinates needs to have a clear edge for internal accurate measurements [56,58]. Thus, in this volume determination method, the image of this boundary is very important.…”

“…Summarizing all the above considerations, the principle of volumes detection and measurement mainly involve three elements: 1) a cylindrical capillary; 2) a fluid boundary as detectable tracking element; 3) an absolute coordinate’s generator in microscopic field of view. The capillary must be fabricated based on PDMS molding techniques [51,52,53,54,55] and it must have finally the imposed cylindrical geometry with the precise dimensions determined using microscopic tools [56,58].…”

“…For the general purpose of generating different experiments focused on the biological environment, we present in this paper the design and fabrication by microwire molding a PDMS-based sensor with circular cross-section microchannel with a good surface quality, for the measurement of microfluidic (nanoliter to picoliter) volumes. To control the microfluidic transport at the nano-, pico- and femto-liter level, we used Microfluidic Pulse Width Modulation (MPWM) [56] system. We designed and fabricated the novel sensor especially to calibrate a microinjection MPWM system that will be used for very high precision intra-cellular insertions.…”