System Support for Generally Programmable Digital Microfluidic Biochip Devices / Cyber-Physical Digital Microfluidics

NSF Awards #1035603 and #1545097 seek to bring software programmability to cyber-physical Laboratories-on-a-Chip (LoCs) that combine electrowetting-on-dielectric (EWoD) technology, driven by active-matrix addressing, with integrated sensing. Compared to traditional benchtop chemistry methods, EWoD-based LoCs reduce reagent consumption and the human error through miniaturization, automation, and programmability. The most recent device generation now features integrated sensors, which can provide real-time feedback to the user or software system that controls the device; thus, the precise manipulation and control of such systems has emerged as a pressing challenge in the burgeoning field of Cyber-Physical Systems (CPS).

Intellectual Merit Award: #1035603 developed a programming model and compiler algorithms to enable the specification of biochemical reactions that include real-time decision-making in response to feedback obtained from sensors integrated into EWoD-based LoC devices; algorithmic challenges that were solved include: fast and effective scheduling algorithms, synergistic operation placement techniques that yielded efficient and provably deadlock-free droplet routing algorithms, and techniques for fault tolerance and recovery.

Award #1545097 will create a domain-specific programming language for EWoD LoCs coupled with a novel fluidic type system to ensure correctness of biochemical reactions and prevent the occurrence of certain types of errors; this award will also fund an investigation into fabrication technologies for EWoD-based LoCs featuring active-matrix addressing, which allows M+N control pins to independently drive MxN electrodes. The PI and Co-PI will validate the language, type system, and working device by programming and executing an opiate detection assay that takes the form of a decision-tree. Successful attainment of the aforementioned goal will demonstrate the effectiveness of domainspecific languages for biomedical CPS applications.

Broader Impacts: LoCs are a potentially lifesaving technology. These awards will lower barriers to entry and increase the productivity of the existing EWoD LoC user base. Future engagement with US companies could forment development of systems that can perform massively parallel analysis of virtually any relevant form of forensic chemistry.

Award #1035603 has trained researchers (graduate students) and undergraduate students through REU supplements and other sources of support such as the California Alliance for Minority Participation (CAMP); the PI has included women and underrepresented minorities among the various trainees. Award #1545097 will continue this successful training program and will enhance ongoing efforts through the creation of student-led R’Courses at UC Riverside and a one-week summer residential program for high school students at the University of Tennessee.

To promote widespread usage of the EWoD-based LoC, the Co-PI will publicly release information necessary to reproduce the device (e.g., process flows and electrical test results), and the PI will publicly disseminate all software artifacts developed in the course of this proposal. During the final year of the project, the PI and Co-PI will present tutorials at scientific meetings to promote widespread adoption and use of these research products in the scientific community