53235102
Module placement for fault-tolerant microfluidics-based biochips
Microfluidics-based biochips are soon expected to revolutionize clinical diagnosis, DNA sequencing, and other laboratory procedures involving molecular biology. Most microfluidic biochips today are based on the principle of continuous fluid flow and they rely on permanently etched microchannels, micropumps, and microvalves. We focus here on the automated design of “digital” droplet-based microfluidic biochips. In contrast to conventional continuous-flow systems, digital microfluidics offers dynamic reconfigurability; groups of cells in a microfluidics array can be reconfigured to change their functionality during the concurrent execution of a set of bioassays. We present a simulated annealing-based technique for module placement in such biochips. The placement procedure not only addresses chip area, but also considers fault tolerance, which allows a microfluidic module to be relocated elsewhere in the system when a single cell is detected to be faulty. Simulation results are presented for case studies involving the polymerase chain reaction and multiplexed in vitro clinical diagnostics.
1293291
Microfluidics-Based Biochips: Technology Issues, Implementation Platforms, and Design-Automation Challenges
Microfluidics-based biochips are soon expected to revolutionize clinical diagnosis, deoxyribonucleic acid (DNA) sequencing, and other laboratory procedures involving molecular biology. In contrast to continuous-flow systems that rely on permanently etched microchannels, micropumps, and microvalves, digital microfluidics offers a scalable system architecture and dynamic reconfigurability; groups of unit cells in a microfluidics array can be reconfigured to change their functionality during the concurrent execution of a set of bioassays. As more bioassays are executed concurrently on a biochip, system integration and design complexity are expected to increase dramatically. This paper presents an overview of an integrated system-level design methodology that attempts to address key issues in the synthesis, testing and reconfiguration of digital microfluidics-based biochips. Different actuation mechanisms for microfluidics-based biochips, and associated design-automation trends and challenges are also discussed. The proposed top-down design-automation approach is expected to relieve biochip users from the burden of manual optimization of bioassays, time-consuming hardware design, and costly testing and maintenance procedures, and it will facilitate the integration of fluidic components with a microelectronic component in next-generation systems-on-chips (SOCs).
13266891
Unified high-level synthesis and module placement for defect-tolerant microfluidic biochips
Microfluidic biochips promise to revolutionize biosensing and clinical diagnostics. As more bioassays are executed concurrently on a biochip, system integration and design complexity are expected to increase dramatically. This problem is also identified by the 2003 ITRS document as a major system-level design challenge beyond 2009. We focus here on the automated design of droplet-based microfluidic biochips. We present a synthesis methodology that unifies operation scheduling, resource binding, and module placement for such "digital" biochips. The proposed technique, which is based on parallel recombinative simulated annealing, can also be used after fabrication to bypass defective cells in the microfluidic array. A real-life protein assay is used to evaluate the synthesis methodology.
16866295
Defect Tolerance Based on Graceful Degradation and Dynamic Reconfiguration for Digital Microfluidics-Based Biochips
Defect tolerance is an important design consideration for microfluidics-based biochips that are used for safety-critical applications. The authors propose a defect-tolerance methodology based on graceful degradation and dynamic reconfiguration. A tile-based biochip architecture is first introduced, which is scalable for large-scale bioassays. A clustered defect model is used to evaluate the graceful-degradation method for tile-based biochips. The proposed schemes ensure that the bioassays mapped to a droplet-based microfluidic array during design can be executed on a defective biochip through operation rescheduling and/or resource rebinding. Real-life biochemical procedures, namely polymerase chain reaction and multiplexed in vitro diagnostics on human physiological fluids, are used to evaluate the proposed defect-tolerance schemes
8296105
Concurrent testing of digital microfluidics-based biochips
We present a concurrent testing methodology for detecting catastrophic faults in digital microfluidics-based biochips and investigate the related problems of test planning and resource optimization. We first show that an integer linear programming model can be used to minimize testing time for a given hardware overhead, for example, droplet dispensing sources and capacitive sensing circuitry. Due to the NP-complete nature of the problem, we also develop efficient heuristic procedures to solve this optimization problem. We apply the proposed concurrent testing methodology to a droplet-based microfluidic array that was fabricated and used to perform multiplexed glucose and lactate assays. Experimental results show that the proposed test approach interleaves test application with the biomedical assays and prevents resource conflicts. The proposed method is therefore directed at ensuring high reliability and availability of bio-MEMS and lab-on-a-chip systems, as they are increasingly deployed for safety-critical applications.
9995821
Testing of droplet-based microelectrofluidic systems
Composite microsystems that integrate mechanical and fluidic components are fast emerging as the next generation of system-on-chip designs. As these systems become widespread in safety-critical biomedical applications, dependability emerges as a critical performance parameter. In this paper, we present a costeffective concurrent test methodology for droplet-based microelectrofluidic systems. We present a classification of catastrophic and parametric faults in such systems and show how faults can be detected by electrostatically controlling and tracking droplet motion. We then present tolerance analysis based on Monte-Carlo simulations to characterize the impact of parameter variations on system performance. To the best of our knowledge, this constitutes the first attempt to define a fault model and to develop a test methodology for droplet-based microelectrofluidic systems.
1341088
An optical characterization technique for hygroscopic expansion of polymers and plastic packages
In this paper, we have described a new simultaneous 3-D optical system for characterizing electronic packages. This optical system is able to capture high resolution, online whole field data set. We are able to use this optical system to determine the coefficient of hygroscopic expansion (CHE) in moulding compound by correlating the weight gain and hygro-strain information obtained. In this study, we have used this optical system to evaluate the hygroscopic expansion of a fully cured moulding compound, XJA-9. We have also studied the effect of moisture diffusion on the deformation of plastic IC package. It was found that moisture diffusion could reverse the warpage of the plastic package. The study showed that moisture may cause severe changes to the internal stress field of plastic packages that would usually occur unnoticed or underestimated.
2604877
A Biometric Key-Binding and Template Protection Framework Using Correlation Filters
We describe a new framework to bind cryptographic keys with biometric signatures using correlation filters. This scheme combines correlation filter based biometric recognition with biometric key-binding while offering template protection, revocability, diversity and security. We demonstrate the effectiveness of our scheme via numerical results on the CMU-PIE face database.
23911088
Robust Ridge Following in Fingerprints
In this paper, we presented an improved approach of minutiae detection by following the ridges Our algorithm is based on the two characteristics of the ridge points on the same ridge: connectivity and randomicity Because our algorithm takes full advantage of the characteristics of the ridge points, it is robust to noise Using our algorithm, good quality ridge images can be obtained which can be used to assist minutiae-based fingerprint matching, or directly used for fingerprint matching Experimental results are included.
41723661
An Adaptive Fingerprint Post-processing Algorithm Based on Mathematical Morphology
In this paper, an adaptive post-processing method using mathematical morphology combined with analyzing the properties of each candidate minutia based on the gray-level image, binary image, local ridge spacing and local orientation is presented to decide whether the minutia is false or true and to eliminate the false one The experiment results demonstrate the effectiveness to reduce the number of false minutiae encountered and improve the thinning fingerprint images at the same time.
206846196
Fingerprint Matching With Rotation-Descriptor Texture Features
A novel texture correlation matching method for fingerprint verification using Fourier-Mellin descriptor and phase-only correlation function is proposed in this paper. Fourier-Mellin descriptor correlation is used to align the template and query fingerprint images and a matching score is obtained. Matching takes about 1 second in Celeron 2.0 GHz processor, and the experimental results show that EER is 3.8%; fusion with minutia matching gets a better result