Microfluidics- The State-of-the-Art Technology for Pharmaceutical Application

Microfluidics (MF) is the science dealing with the behavior, precise control, and manipulation of fluids as well as particles on the scale of tens to hundreds of micrometers. It is also utilized for chemical and biological applications, usually called micro–Total Analysis Systems (mTAS) or Lab-on-a-chip (LOC). MF is a fascinating and capable technology with various superior benefits compared to conventional macro-scale platforms, such as the lesser requirement of sample and reagent volumes, higher sensitivity, low cost, portability, faster processing of samples and potential to be automated and highly integrated to reduce human errors. The concept of transformation of meso to nanoliters using MF technology has shown its potential in the healthcare system for early diagnosis, and personalized medicine. The integrated multifunctional system with parallelization provides a better and faster process control. Minimization of the consumption of fluid makes the technology safer in every aspect of the development process, analysis, and storage. The impressive improvement in patient care and monitoring has led to the commercial motivation of the pharmaceutical industry to develop new drugs and modify existing products with better efficacy and safety in a cost-effective manner using MF technologies. Hence, the present review briefs on the applications of MF technology in the key issues of the drug discovery process, overcoming the limitations of development of analytical procedures and prosperous pharmaceutical manufacturing for novel controlled and targeted release dosage forms to fabricate quality products.

Wireless bipolar electrode-based textile electrofluidics: towards novel micro-total-analysis systems

Wireless bipolar electrochemistry on a surface-accessible textile-based electrofluidic 3D construct.

Silicon Nanofluidic Membrane for Electrostatic Control of Drugs and Analytes Elution

Individualized long-term management of chronic pathologies remains an elusive goal despite recent progress in drug formulation and implantable devices. The lack of advanced systems for therapeutic administration that can be controlled and tailored based on patient needs precludes optimal management of pathologies, such as diabetes, hypertension, rheumatoid arthritis. Several triggered systems for drug delivery have been demonstrated. However, they mostly rely on continuous external stimuli, which hinder their application for long-term treatments. In this work, we investigated a silicon nanofluidic technology that incorporates a gate electrode and examined its ability to achieve reproducible control of drug release. Silicon carbide (SiC) was used to coat the membrane surface, including nanochannels, ensuring biocompatibility and chemical inertness for long-term stability for in vivo deployment. With the application of a small voltage (≤ 3 V DC) to the buried polysilicon electrode, we showed in vitro repeatable modulation of membrane permeability of two model analytes—methotrexate and quantum dots. Methotrexate is a first-line therapeutic approach for rheumatoid arthritis; quantum dots represent multi-functional nanoparticles with broad applicability from bio-labeling to targeted drug delivery. Importantly, SiC coating demonstrated optimal properties as a gate dielectric, which rendered our membrane relevant for multiple applications beyond drug delivery, such as lab on a chip and micro total analysis systems (µTAS).

Understanding Interdependencies between Mechanical Velocity and Electrical Voltage in Electromagnetic Micromixers

Micromixers are critical components in the lab-on-a-chip or micro total analysis systems technology found in micro-electro-mechanical systems. In general, the mixing performance of the micromixers is determined by characterising the mixing time of a system, for example the time or number of circulations and vibrations guided by tracers (i.e., fluorescent dyes). Our previous study showed that the mixing performance could be detected solely from the electrical measurement. In this paper, we employ electromagnetic micromixers to investigate the correlation between electrical and mechanical behaviours in the mixer system. This work contemplates the “anti-reciprocity” concept by providing a theoretical insight into the measurement of the mixer system; the work explains the data interdependence between the electrical point impedance (voltage per unit current) and the mechanical velocity. This study puts the electromagnetic micromixer theory on a firm theoretical and empirical basis.

Design and Comparison of Resonant and Non-Resonant Single-Layer Microwave Heaters for Continuous Flow Microfluidics in Silicon-Glass Technology

This paper presents a novel concept for the co-design of microwave heaters and microfluidic channels for sub-microliter volumes in continuous flow microfluidics. Based on the novel co-design concept, two types of heaters are presented, co-designed and manufactured in high-resistivity silicon-glass technology, resulting in a building block for consumable and mass-producible micro total analysis systems. Resonant and non-resonant co-planar waveguide transmission line heaters are investigated for heating of sub-micro-liter liquid volumes in a channel section at 25 GHz. The heating rates of 16 and 24 °C/s are obtained with power levels of 32 dBm for the through line and the open-ended line microwave heater, respectively. The heating uniformity of developed devices is evaluated with a Rhodamine B and deionized water mixture on a micrometer scale using the microwave-optical measurement setup. Measurement results showed a good agreement with simulations and demonstrated the potential of microwave heating for microfluidics.