Droplet-based "digital" microfluidics technology has now come of age and software-controlled biochips for healthcare applications are starting to emerge. However, today's digital microfluidic biochips suffer from the drawback that there is no feedback to the control software from the underlying hardware platform. Due to the lack of precision inherent in biochemical experiments, errors are likely during droplet manipulation, but error recovery based on the repetition of experiments leads to wastage of expensive reagents and hard-to-prepare samples. By exploiting recent advances in the integration of optical detectors (sensors) in a digital microfluidics biochip, we present a "physicalaware" system reconfiguration technique that uses sensor data at intermediate checkpoints to dynamically reconfigure the biochip. A cyberphysical re-synthesis technique is used to recompute electrode-actuation sequences, thereby deriving new schedules, module placement, and droplet routing pathways, with minimum impact on the time-to-response.

Abstract-Microfluidics-based biochips are revolutionizing highthroughput sequencing, parallel immunoassays, clinical diagnostics, and drug discovery. These devices enable the precise control of nanoliter volumes of biochemical samples and reagents. Compared to conventional laboratory procedures, which are cumbersome and expensive, miniaturized biochips offer the advantages of higher sensitivity, lower cost due to smaller sample and reagent volumes, system integration, and less likelihood of human error. This embedded tutorial paper provides an overview of droplet-based "digital" microfluidic biochips. It describes emerging computer-aided design (CAD) tools for the automated synthesis and optimization of biochips from bioassay protocols. Recent advances in fluidic-operation scheduling, module placement, droplet routing, pin-constrained chip design, and testing are presented.

As technology advances into nanometer territory, the antenna problem has caused significant impact on routing tools. The antenna effect is a phenomenon of plasmainduced gate oxide degradation caused by charge accumulation on conductors.It directly influences reliability, manufacturability and yield of VLSI circuits, especially in deep-submicron technology using high density plasma. Furthermore, the continuous increase of the problem size of IC routing is also a great challenge to existing routing algorithms. In this paper, we propose a novel framework for multilevel full-chip routing with antenna avoidance using built-in jumper insertion approach. Compared with the state-of-the-art multilevel routing, the experimental results show that our approach reduced 100% antenna-violated gates and results in fewer wirelength, vias, and delay increase.

As the microfluidic technology advances, the design complexity of digital microfluidic biochips (DMFB) are expected to explode in the near future. One of the most critical challenges for DMFB design is the droplet routing problem, which schedules the movement of each droplet in a time-multiplexed manner. In this paper, we propose a fast routability-and performancedriven droplet router for DMFBs. The main contributions of our work are: (1) a global moving vector analysis for constructing preferred routing tracks to minimize the number of used unit cells; (2) an entropy-based equation to determine the routing order of droplets for better routability; (3) a routing compaction technique by dynamic programming to minimize the latest arrival time of droplets. Experimental results show that our algorithm achieves 100% routing completion for all test cases on three Benchmark Suites while the previous algorithms are not. In addition to routability, compared with the state-of-theart high-performance routing on the Benchmark Suite I [3], the experimental results still show that our algorithm performed better in runtime by 40%, reduced the latest arrival time by 21%, reduced the used unit cells by 10%. Furthermore, experiment results on Benchmark Suite II and III are also very promising. Based on the evaluation of three Benchmark Suites, our algorithm demonstrates the efficiency and robustness of handling complex droplet routing problem over the existing algorithms.

No abstract

In this paper we are interested in flow-based microfluidic biochips, which are able to integrate the necessary functions for biochemical analysis on-chip. In these chips, the flow of liquid is manipulated using integrated microvalves. By combining several microvalves, more complex units, such as micropumps, mixers, and multiplexers, can be built. In this paper we propose, for the first time to our knowledge, a top-down control synthesis framework for the flow-based biochips. Starting from a given biochemical application and a biochip architecture, we synthesize the control logic that is used by the biochip controller to automatically execute the biochemical application. We also propose a control pin count minimization scheme aimed at efficiently utilizing chip area, reducing macro-assembly around the chip and enhancing chip scalability. We have evaluated our approach using both real-life applications and synthetic benchmarks.

No abstract

No abstract