David W.M. Marr

Professor

BS - University of California, Berkeley
MS, PhD - Stanford University
Post-Doctoral Study - Raychem Corporation
Education Abroad - Georg-August-Universität Göttingen (Germany)

Research Description

The controlled assembly of colloidal particles has received significant attention in recent years because of their potential application as nano- and micro-structured materials. To vary their structure and behavior, we employ external fields, including applied time-varying electromagnetic, electric, and magnetic fields. One technique that we use to great extent is optical trapping in which a focused laser is used to manipulate individual colloidal particles, as well as a “tractor beam” like approach where the laser is used to control large numbers of colloids simultaneously. Funded in recent years by the NIH, NSF and NASA for microfluidic applications, our goal is the creation of technologically relevant colloidal-based structures including micron-scale devices such as pumps and valves, photonic materials, and optical-based separators for isolation and manipulation of individual cells for bioanalysis.

selected Publications

T. Sawetzki, S. Rahmouni, C. Bechinger, D.W.M. Marr, “In-Situ Assembly of Linked Geometrically-Coupled Microdevices”, Proceedings of the National Academy of Sciences of the USA, 2008, 150, 20141-20145. press release available here.

R.W. Applegate Jr., J. Squier, T. Vestad, J. Oakey, D.W.M. Marr, “Fiber-Focused Diode-Bar Optical Trapping for Microfluidic Flow Manipulation”, Applied Physics Letters, 2008, 92, 013904 (Also featured in the Virtual Journal of Biological Physics Research the Virtual Journal of Nanoscience and Technology).

D. Schafer, E.A. Gibson, W. Amir, R. Erikson, J. Lawrence, T. Vestad, J.A. Squier, R. Jimenez, D.W.M. Marr, “Three-dimensional Chemical Concentration Maps in a Microfluidic Device using Two-photon Absorption Fluorescence Imaging”, Optics Letters, 2007, 32, 2568-2570.

R.W. Applegate Jr., J. Squier, T. Vestad, J. Oakey, D.W.M. Marr, P. Bado, M.A. Dugan, A.A. Said, “Microfluidic Sorting System Based on Optical Waveguide Integration and Diode Laser Bar Trapping”, Lab on a Chip, 2006, 6, 422.

T. Gong, D.T. Wu, D.W.M. Marr, “Electric Field Reversible Three-Dimensional Colloidal Crystals”, Langmuir, 2003, 19, 5967 (cover article).

A. Terray, J. Oakey, D.W.M. Marr, “Microfluidic Control Using Colloidal Devices”, Science, 2002, 296, 1841.(Abstract, Full Text). (Also featured in Technology Research News)