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Introduction
Published in Sudip Poddar, Bhargab B. Bhattacharya, Error-Tolerant Biochemical Sample Preparation with Microfluidic Lab-on-Chip, 2022
Sudip Poddar, Bhargab B. Bhattacharya
DMFBs consist of a patterned array of electrodes that can be electrically actuated to perform various fluidic operations [23, 24]. This technology is referred to as “digital microfluidics” since one can manipulate discrete-volume droplets on the electrodes in a “digitized” manner. The top-view of a digital microfluidic biochip, and the execution of basic fluidic operations (dispensing, transporting, mixing, splitting, and sensing) are shown in Fig. 1.1(a) for demonstration. By applying time-varying voltage (low/high) to the electrodes, DMFBs can execute a number of bioassays in parallel [147]. DMFBs contain several microfluidic units including input and waste reservoirs, dispensers, mixers, splitters, sensors, thermal units (heater/cooler), as illustrated in Fig. 1.1(a). For example, we have shown two input reservoirs (used for dispensing the droplets) and one waste reservoir (used to drain unnecessary intermediate droplets from the chip). Sensors, which are used to measure concentration, pH, droplet-volume, other physical or chemical properties of fluid droplets, are placed in specified locations on the biochip. Droplet-transportation paths and the location of mixer/splitter modules can be emulated anywhere in vacant regions of a DMFB subject to neighborhood rules, and thus can be dynamically reconfigured on-chip if necessary, e.g., when some electrodes become unusable because of structural degradation or electrical faults.
Security Vulnerabilities of Quantitative-Analysis Frameworks
Published in Mohamed Ibrahim, Krishnendu Chakrabarty, Optimization of Trustworthy Biomolecular Quantitative Analysis Using Cyber-Physical Microfluidic Platforms, 2020
Mohamed Ibrahim, Krishnendu Chakrabarty
Advances in digital-microfluidics technology offer tremendous benefits for enzymatic analysis, DNA analysis, immunoassays, toxicity monitoring, and clinical diagnostics. It has been also considered as a means to counter bio-terrorism [69]. On the other hand, since standard CMOS is an attractive technology option for DMFBs [187], they may be a target of attacks demonstrated on CMOS ASICs [130] and FPGAs [267]. Similar to their counterparts in CMOS chip (ASIC or FPGA) design, attacks on DMFBs can target stealing of hardware intellectual property (IP) [97], chip and IP reverse engineering [43; 207], and chip counterfeiting [89]. However, in this section, we assess the security of DMFBs against attacks that are unique to biochip-based bioassays such as bioassay result-manipulation attacks.
Introduction
Published in Krishnendu Chakrabarty, Fei Su, Digital Microfluidic Biochips, 2018
Krishnendu Chakrabarty, Fei Su
The so-called first generation microfluidic biochips were based on continuous liquid flow through fabricated microchannels, and they were designed for simple biochemical analyses or assays [3,4]. Recently, a second-generation paradigm has emerged that manipulates liquids as discrete nanoliter droplets [9,10]. Following the analogy of digital electronics, this technology is referred to as digital microfluidics. In contrast to continuous-flow biochips, digital microfluidic biochips offer a scalable system architecture based on a two-dimensional microfluidic array of identical basic cells. Since each droplet (or groups of droplets) can be controlled independently, these “digital” systems also have dynamic reconfigurability, whereby groups of cells in a microfluidic array can be reconfigured to change their functionality during the concurrent execution of a set of bioassays. Due to their inherent properties of dynamic reconfigurability and architectural scalability, digital biochips can be used as programmable “microfluidic processors,” especially for massively parallel DNA analysis, automated drug discovery, and real-time biomolecular detection.
Sequentially automated extraction of nucleic acids with magnetophoresis in microfluidic chips
Published in Instrumentation Science & Technology, 2023
M. Kashif Siddique, Ruizhi Lee, Songjing Li, Lin Sun
Automated systems have revolutionized the field of microfluidics, leveraging advanced technology to precisely control fluid flow and manipulation within microfluidic devices.[28,29] These systems encompass a wide range of components, including pumps, valves, and actuators, and utilize sophisticated software to facilitate monitoring and control of the system. Notably, a digital microfluidic platform, which uses electronic control to manipulate fluid droplets on a chip, is a noteworthy example of an automated microfluidic system.[30] This platform is widely utilized in several applications, such as lab-on-a-chip devices for chemical and biological analysis, as well as high-throughput screening of drugs. Additionally, integrating robotics and machine learning in microfluidics has emerged as a promising trend. Therefore, automation in microfluidics significantly increases the efficiency and precision of experiments and applications in the field. The automated system designed in this study extracts nucleic acid from biomedical samples using magnetic bead extraction methodology.[31,32]
Low-cost digital microfluidic approach on thin and pliable polymer films
Published in Instrumentation Science & Technology, 2022
Dongping Chai, Jiaxi Jiang, Yiqiang Fan
Compared with the conventional closed-channel microfluidic devices continuously handling the fluid flow, the digital microfluidic chips (DMF) are able to precisely manipulate the discrete fluid flow (i.e., droplets) in micro- or nano-liter scale without physical pumps, valves, or complex microchannel structures.[1] Digital microfluidic technology is developing rapidly in recent years and has been used in DNA extraction,[2] nucleic acid amplification,[3] loop-mediated isothermal amplification (LAMP),[4] protein study,[5] enzymatic assay,[6] immunoassays,[7] cell-based assays,[8] and chemical synthesis.[9]
An Efficient Multiple Fault Detection Technique in Digital Microfluidic Biochips
Published in IETE Journal of Research, 2021
Sagarika Chowdhury, Piyali Datta, Rajat Kumar Pal, Goutam Saha
Digital Microfluidics is an emerging technology that provides micro- and nano-liter scale fluid-handling potential, like automation, miniaturization, and integration of complex biochemical protocols on a chip. Digital Microfluidic Biochip (DMFB) utilizes the phenomenon of electro-wetting to manipulate biological samples in the shape of tiny droplets on a two dimensional (2D) electrode array. A unit cell in the array comprises a pair of parallel plates acting as a pair of electrodes; the bottom plate contains a patterned array of individually controlled electrodes and the top plate works as a continuous ground electrode. Droplets are moved by applying external control voltages to the electrodes to perform basic fluidic operations like mixing of samples and reagents and routing of droplets that need to move [1].