A Field-Programmable Pin-Constrained Digital Microfluidic Biochip

1. A Field-ProgrammablePin-Constrained Digital Microfluidic Biochip Dan Grissom and Philip Brisk University of California, Riverside Design Automation Conference Austin, TX, USA, June 4, 2013

2. Digital Microfluidic Biochips (DMFB) 101 Applications A Digital Microfluidic Biochip Basic Microfluidic Operations

3. Direct Addressing Cost Problem • Problem: • Direct-addressing wire-routing is expensive (m × n wires) m DA: 100 pins Vs. PC: ≤ 28 pins Many PCB Layers n Few PCB Layers Direct Addressing DMFB Pin-Constrained DMFB

4. Pin-Constrained Flexibility Problem • Problem: • Pin-constrained devices are application specific ( < m × n wires) I1 2 3 1 5 6 2 1 I2 1 2 3 4 7 1 3 2 O1 Direct-Addressing Synthesis Pin-Constrained Mapping/Reduction Application Specific!

5. Goal Statement • Goal: 1) Inexpensive, 2) general-purpose DMFBs • Why: • Affordable/accessible to poor/remote communities • Encourage new applications Generally Programmable Few PCB Layers Best of BOTH Worlds!

6. The Solution • Solution: Field-programmable, pin-constrained (FPPC) DMFB • Mapped for basic operations instead of specific assays • Flexibility & reduced pin-count (PCB layers)

7. FPPC DMFB Features • Complete Synthesis • List Scheduling onto discrete resources • e.g. 4 mixers, 6 split/store/detect modules • Other schedulers acceptable • Simple, fast left-edge binding I1 I2 I1 [0,1) I2 [0,1) M1 M1 [1,4) Det1 Det1 [4,9)

8. FPPC DMFB Features (cont’d) • Complete Synthesis (cont’d) • Sequential router (I/OModule, ModuleModule, ModuleI/O) • Horizontal/vertical routing channels • 3-pins per channel • Routing cycles (ms) << operation time-steps (s) • No significant gains by parallel routing • Well-defined module I/O • See Paper/Poster • Well-defined deadlock-resolution policies • See Paper/Poster Desired Motion 1 2 1 2 1 3 1 2 3 1 2-Phase Bus 3-Phase Bus Vertical Routing Channels Horizontal Routing Channels

9. FPPC DMFB Features (cont’d) • Resizing without changing synthesis methods • DMFB Elongation • Module-Size Variation Allows user to buy off-the-shelf DMFB with enough resources to run their assay.

10. Experimental Results • FPPC DMFB vs. Direct-Addressing DMFB [1] Negative Impact on Routing Offset by Positive Impact on Operation Time Yields Neutral Effect on Overall Assay Time [1] D. Grissom and P. Brisk. Fast online synth. of generally prog. digital microfluidic biochips. CODES+ISSS 2012.

11. Experimental Results • FPPC DMFB vs. Direct-Addressing DMFB Neutral Effect Considered Positive Because of Electrode/Pin-Count Reduction

12. Pin-Constrained Comparison Application-specific Pin-constrained Designs: • Pin-usage for FPPC design on par with optimized PC DMFBs • FPPC can perform general assays vs. optimized PC DMFB’s 3 specific assays • Better schedulers could reduce size needed Multiplexed Immunoassay DMFB PCR Assay DMFB Multi-Functional DMFB Protein Dilution Assay DMFB Smallest FPPC to perform Immuo/PCR/Protein: 12x18 [2] T. Xu and K. Chakrabarty. Broadcast electrode-addressing for pin-constrained multi-functional digital microfluidic biochips. DAC, 2008. [3] Y. Luo and K. Chakrabarty. Design of pin-constrained general-purpose digital microfluidic biochips. DAC, 2012.

13. Conclusion • New DMFB design • Pin-constrained to OPERATIONS • Pin-constrained design  Inexpensive • Field-programmable  Execute general assay s • Can buy an inexpensive, off-the-shelf device and run desired assay • Design facilitates different DMFB and module sizes • Best of both worlds • Similar assay times and flexibility to recent direct-addressing DMFBs • Similar pin-counts to recent pin-constrained designs

14. Thank You http://microfluidics.cs.ucr.edu • DMFB simulator and high-quality visualizations • Open-source code and Windows binaries • Includes a number of synthesis methods including source code for DAC 2013 • Great for research implementations, teaching (project course work), high-quality graphics (for papers and presentations) and more…

15. Thank You