Recent developments in microfluidic large scale integration

Abstract

In 2002, Thorsen et al. integrated thousands of micromechanical valves on a single microfluidic chip and demonstrated that the control of the fluidic networks can be simplified through multiplexors [1]. This enabled realization of highly parallel and automated fluidic processes with substantial sample economy advantage. Moreover, the fabrication of these devices by multilayer soft lithography was easy and reliable hence contributed to the power of the technology; microfluidic large scale integration (mLSI). Since then, mLSI has found use in wide variety of applications in biology and chemistry. In the meantime, efforts to improve the technology have been ongoing. These efforts mostly focus on; novel materials, components, micromechanical valve actuation methods, and chip architectures for mLSI. In this review, these technological advances are discussed and, recent examples of the mLSI applications are summarized. Recent advancements in microfluidic technologies have created new opportunities in the fields of biology and chemistry through miniaturization and automation of common processes, including mixing, metering, trapping, reaction, filtering, and separation, among others. Microfluidic large scale integration (mLSI) enables the fabrication of microfluidic chips containing hundreds or more of these functions using well-established lithography techniques, similar in principle to electronic LSI in the semiconductor industry [1]. Small feature dimensions, abundant spatial parallelism, and control over fluid flow provide mLSI technology with advantages such as high throughput, precise metering, automation and low reagent consumption. The implications of mLSI technology can especially be seen in recent advances in single cell, genomic, and protein analysis.

Microfluidic very large-scale integration for biochips: Technology, testing and fault-tolerant design

“…The external pneumatic air pressure that is applied to the membrane is controlled using a solenoid valve. Other valve technologies have been proposed, see [28] for a survey.…”

“…We will refer to these results when describing the design tasks. An overview of the recent developments in mVLSI is presented in [28]. Given the system specifications (e.g., application requirements, chip area), the mVLSI design flow starts with the schematic design (netlist) of the required biochip.…”

“…For a survey of recent component developments, see [28]. A mixer is a key requirement for mVLSI biochips where fluid flow is laminar thus mixing only occurs by diffusion.…”

“…Based on the basic micromechanical valve operation principle, many components have been developed, such as, pump, rotary mixer, multiplexer, sieve valves, filter [6], [28]. For a survey of recent component developments, see [28].…”

Stimulus-active polymer actuators for next-generation microfluidic devices

“…However, despite significant research activities in this highly multidisciplinary field over more than two decades, only few concepts have ultimately reached the level of commercialization. Studies addressing this issue [3,4] identified the lack of standardization and integration as the main barriers to acceptance by the end-user and thus to commercial breakthrough: After acquiring one of the few commercially available microfluidic products, the operator may face difficulties in connecting the microfluidic device to ancillary hardware, such as external supplies, valves, pumps and other microfluidic components [5]. In contrast to assessments in the early stages [6], which predicted silicon-based microsystem technology as the most promising approach for microfluidic applications, soft-matter-based and hybrid solutions have become more significant [7].…”