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

Ardeleanu Ardeleanu,Alhalaili Alhalaili,Diaconu Diaconu,Lungu Lungu,Udroiu Udroiu,Vidu Vidu,Mihai Mihai,Popescu Popescu

doi:10.3390/s19224886

Abstract

In order for automatic microinjection to serve biomedical and genetic research, we have designed and manufactured a PDMS-based sensor with a circular section channel using the microwire molding technique. For the very precise control of microfluidic transport, we developed a microfluidic pulse width modulation system (MPWM) for automatic microinjections at a picoliter level. By adding a computer-aided detection and tracking of fluid-specific elements in the microfluidic circuit, the PDMS microchannel sensor became the basic element in the automatic control of the microinjection sensor. With the PDMS microinjection sensor, we precise measured microfluidic volumes under visual detection, assisted by very precise computer equipment (with precision below 1 μm) based on image processing. The calibration of the MPWM system was performed to increase the reproducibility of the results and to detect and measure microfluidic volumes. The novel PDMS-based sensor system for MPWM measurements of microfluidic volumes contributes to the advancement of intelligent control methods and techniques, which could lead to new developments in the design, control, and in applications of real-time intelligent sensor system control.

Highlights

The increasing demands for a complete and real-time diagnosis of a larger population and the improvement of the quality of life in general has led scientists from all over the world to study and develop multidisciplinary science and technologies [1,2,3,4,5,6]
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 volumes
By extracting the wire under the conditions of swelling of PDMS, the longitudinal micro-irregularities have been created that do not affect the laminar flow of the fluid, but for the precise determination of the maximum error affecting the calculation of the fluid volume, the variation of the channel section due to the roughness can be taken into account

Summary

Introduction

The increasing demands for a complete and real-time diagnosis of a larger population and the improvement of the quality of life in general has led scientists from all over the world to study and develop multidisciplinary science and technologies [1,2,3,4,5,6]. The LOC offers a precise analysis of a large numbers of individual molecules and cells, flexibility of device design, high experimental control, and reduces measurement times [4,5,12]. Another advantage of the microfluidic cell culture device is the ability to incorporate analytical biosensors into the culture platform, combining, in a non-invasive way, living cells and sensors for detecting cellular physiological parameters and analyzing external stimuli in situ [12,13] LOC devices, including microfluidic ones, have many advantages such as reducing the use of chemicals (reduced sample and reagent usage) that can be rare, expensive and polluting, reducing waste production, miniaturization, integration, portability, and automation [4,7,8,11].

Methods

Results

Conclusion