Microfluidic channels for hassle-free drug testing ©ankitaryan
Although Microfluidics sounds like a sci-fi word and a strictly laboratory-centred phenomenon, it is surprisingly all around us! Microfluidics typically deals with the manipulation of fluids in nanolitres at a micro-scale and it has played a vital role in sustaining life on the earth for about 450 million years since first plants appeared on the land. Be it the transport of food and nutrients in plants or the flow of blood in capillaries, microfluidics in inside almost every biological system but humans were unable to tap its true potential due to the technological limitations in the fabrication of micro-structures until late 1950’s when inkjet printers came into the picture which involved flowing ink through very small tubes for printing.
Microfluidics has come a long way since then and the number of commercial microfluidic devices has significantly risen in the past years. The most prevalent method of fabrication of microfluidic channels involves making a positive photolithography mold using a patterned mask and then using PDMS (poly dimethyl siloxane) to make depressions and sealing the device with glass/PDMS using plasma bonding. Though this method is very precise, it limits the reproducibility of the device as PDMS is fragile and making a device with sub-100 micron features requires a significant amount of skill and clean room facilities.
3D printing offers a solution to this problem as its precise, automatic and works fine in relatively ‘less clean’ environments. The print-resolution and print-speed used to be challenge earlier but with the recent SLA (Stereolithography) and Multijet 3D printing, we can make sub-500 micron channels/molds with ease (sub-100 micron molds can also be made using Ultra High-Resolution DLP-SLA 3D printers though they require surface treatment for proper curing).
Moreover, there have been significant recent developments in the field of LOC (Lab-on-a-Chip) Microfluidic devices for POC( Point-of-Care) Diagnosis which essentially means that all the fluid-based medical diagnostics could be performed using a hand-held device with rapid results; and with the recent microfluidics fabrication techniques, these devices could be made cheaper. So, anyone could do the tests for diseases like malaria, dengue, TB, HIV etc. at home with negligible costs and this could potentially save millions of lives and significantly improve the standard of living in the developing nations.