Microfluidic technologies: from fundamental principles to advanced fabrication and applications

Abstract Conventional drug delivery systems, model study systems, drug analysis systems and drug interactions systems have been in use since ages. But these conventional methods struggle with significant limitations like lack of precise targeting, irregular release profiles, inconsistent data analysis, unpredictable throughputs and high dosage requirements that leads to systematic toxicity. Moreover, challenges in achieving site-specific therapy can result in poor therapeutic outcomes and noncompliance of patients. This calls for an evident necessity of a new platform that can improve bioavailability, allow precise drug targeting, precise drug analysis, controlled drug loading and release and also accurate data predictions. Microfluidics, emerging as a technology with promising outcomes can tackle such barriers and hurdles that are usually faced in the conventional techniques. By manipulating fluid handling at microscale level, it is able to create precise and scalable drug delivery devices and drug efficiency prediction platforms like microparticles, microneedles, organ-on-a-chip, lab-on-a-chip, wearable devices etc. Microfluidics operates on the principle of fluid dynamics, where its reliability on low Reynolds number to achieve laminar flow acting as the main driving force followed by electrokinetic fluid handling, capillary action and centrifugal force. Microfluidics engineered systems are used in various fields in oncology for targeting tumour, blood analysis, tailoring of personalised medicines, preclinical studies and much more. So, fabrication of devices of such dynamic also require the correction selection of the technique. Fabrication techniques of microfluids have also evolved a long way from conventional ones like photolithography, soft lithography, etching to developments like laser micromachining, nanofabrication, 3D printing and wearable microfluidics. Recent advancements of 4D printing, and incorporation of AI driven microfluidic chip has also strengthened the possibility of more future furtherance in the fabrication of a perfect microfluidics devices to almost eradicate all conventional limitations.