Dr. Chuan Pu Profile

Dr. Chuan Pu

Director of Engineering at Microsoft Technology Ctr

SPIE Involvement:

Author

Proceedings Article | 18 August 2005 Paper

Oscillating optical tweezer-based 3-D confocal microrheometer for investigating the intracellular micromechanics and structures

H. Ou-Yang, E. Rickter, C. Pu, O. Latinovic, A. Kumar, M. Mengistu, L. Lowe-Krentz, S. Chien

Proceedings Volume 5930, 593004 (2005) https://doi.org/10.1117/12.618108

KEYWORDS: Optical tweezers, Particles, Confocal microscopy, Optical amplifiers, Cytoskeletons, Microscopes, Proteins, Mirrors, Phase shifts, Motion measurement

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Mechanical properties of living biological cells are important for cells to maintain their shapes, support mechanical stresses and move through tissue matrix. The use of optical tweezers to measure micromechanical properties of cells has recently made significant progresses. This paper presents a new approach, the oscillating optical tweezer cytorheometer (OOTC), which takes advantage of the coherent detection of harmonically modulated particle motions by a lock-in amplifier to increase sensitivity, temporal resolution and simplicity. We demonstrate that OOTC can measure the dynamic mechanical modulus in the frequency range of 0.1-6,000 Hz at a rate as fast as 1 data point per second with submicron spatial resolution. More importantly, OOTC is capable of distinguishing the intrinsic non-random temporal variations from random fluctuations due to Brownian motion; this capability, not achievable by conventional approaches, is particular useful because living systems are highly dynamic and often exhibit non-thermal, rhythmic behavior in a broad time scale from a fraction of a second to hours or days. Although OOTC is effective in measuring the intracellular micromechanical properties, unless we can visualize the cytoskeleton in situ, the mechanical property data would only be as informative as that of "Blind men and the Elephant". To solve this problem, we take two steps, the first, to use of fluorescent imaging to identify the granular structures trapped by optical tweezers, and second, to integrate OOTC with 3-D confocal microscopy so we can take simultaneous, in situ measurements of the micromechanics and intracellular structure in living cells. In this paper, we discuss examples of applying the oscillating tweezer-based cytorheometer for investigating cultured bovine endothelial cells, the identification of caveolae as some of the granular structures in the cell as well as our approach to integrate optical tweezers with a spinning disk confocal microscope.

Proceedings Article | 3 September 2002 Paper

Technologies for large-scale optical switching: recent advances and future prospects

Chuan Pu, Chris Wu

Proceedings Volume 4907, (2002) https://doi.org/10.1117/12.482292

KEYWORDS: Mirrors, Microelectromechanical systems, Switches, Switching, Networks, Packaging, Optical switching, Silicon, Optical components, Control systems

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Proceedings Article | 11 July 2002 Paper

MEMS for optical communication: present and future

Chuan Pu, Shi-sheng Lee, Sangtae Park, Patrick Chu, Igal Brener

Proceedings Volume 4870, (2002) https://doi.org/10.1117/12.475515

KEYWORDS: Microelectromechanical systems, Mirrors, Switches, Wavelength division multiplexing, Tunable lasers, Polarization, Optical networks, Optical communications, Optical switching, Wavelength division multiplexing networks

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Proceedings Article | 21 November 2001 Paper

MEMS for optical networking: vast promises amid vaster promises

Shi-sheng Lee, Sangtae Park, Patrick Chu, Chuan Pu, Lih-Yuan Lin, Evan Goldstein

Proceedings Volume 4592, (2001) https://doi.org/10.1117/12.448977

KEYWORDS: Microelectromechanical systems, Switches, Mirrors, Optical networks, Wavelength division multiplexing, Polarization, Dispersion, Switching, Attenuators, Promethium

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Proceedings Article | 2 October 2001 Paper

MOEMS: enabling technologies for large optical cross-connects

Patrick Chu, Shi-sheng Lee, Sangtae Park, Ming-Ju Tsai, Igal Brener, David Peale, Robert Doran, Chuan Pu

Proceedings Volume 4561, (2001) https://doi.org/10.1117/12.443075

KEYWORDS: Mirrors, Microelectromechanical systems, Switches, Control systems, Switching, Microopto electromechanical systems, Electronics, Optical switching, Actuators, Optical networks

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Showing 5 of 6 publications

Conference Committee Involvement (1)

Optical Transmission, Switching, and Subsystems

4 November 2003 | Wuhan, China

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