Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences


UC Berkeley


Research Projects

Light-Actuated Digital Microfluidics (Optoelectrowetting)

Shao Ning Pei, Justin K Valley and Ming C. Wu

Berkeley Sensor and Actuator Center

The ability to quickly perform large numbers of chemical and biological reactions in parallel using low reagent volumes is a field well addressed by droplet-based digital microfluidics. Compared to continuous flow-based techniques, digital microfluidics offers the added advantages such as individual sample addressing and reagent isolation. We are developing a light-actuated digital microfluidics device (also known as optoelectrowetting) that optically manipulates nano- to micro-liter scale aqueous droplets on the device surface. The device possesses many advantages including ease of fabrication (no lithography required) and the ability for real-time, reconfigurable, large-scale droplets control (simply by altering the low-intensity projected light pattern). We hope to develop Light-Actuated Digital Microfluidics into a powerful platform for lab-on-a-chip (LOC) applications.

Figure 3
Figure 3: Device structure and actuation mechanism

Figure 4
Figure 4: a) Merging and b) splitting of droplets

Figure 5
Figure 5: Array formation of droplets

Figure 6
Figure 6: High-speed parallel manipulation

S. N. Pei, J. K. Valley, S. L. Neale, A. Jamshidi, H.-Y. Hsu, and M. C. Wu, "Light-actuated digital microfluidics for large-scale, parallel manipulation of arbitrarily sized droplets," in Micro Electro Mechanical Systems (MEMS), 2010 IEEE 23rd International Conference on, pp. 252-255
J. K. Valley, S. N. Pei, A. Jamshidi, H.-Y. Hsu, and M.C. Wu, “A unified platform for optoelectrowetting and optoelectronic tweezers”, in press, Lab on a Chip, 2011
P.Y. Chiou, S. Park, and M.C. Wu, “Continuous optoelectrowetting for picoliter droplet manipulation,” Applied Physics Letters, vol. 93, 2008, p. 221110