Integrated Microfluidic Flow Sensor for LAB-oN-CHIP and PoINT-oF-CARE Applications

Abstract

The results of the development and manufacture of an integrated membrane-free sensor for the control of accurate dilution of liquid samples on the microfluidic chip are presented. The proposed type of devices is intended for direct precise measurements of liquid flow rate in microchannels of laboratories-on-chip, including point-of-care systems. The sensor topology was optimized based on the numerical simulation results and technological requirements. The main characteristic of the developed sensor is the lack of a membrane in the design while maintaining the sensitivity and accuracy of the device at the level of a commercial membrane analogue. The fully biocompatible sensor was manufactured using standard microelectronics and soft lithography technologies. In order to optimize the sensor design, 32 different topologies of the device were tested. The integration of the flow sensors on the chip allows to significantly reduce the dead volume of the hydrodynamic system and to control the amount of liquid entering the individual reservoirs of the microfluidic chip. The sensor occupies an area of (210 x 140) um2 in the channel and is characterized by a relative error of 5% in the flow rate range of 100-1000 ul/min. microfluidics, lab-on-chip, calorimetric flow sensor, thermoresistive sensor, numerical simulation, hydrodynamics, complementary metal-oxide-semiconductor, microtechnologies Devices were made at the BMSTU Nanofabrication Facility (FMN Laboratory, FMNS REC, ID 74300).