Hopping mechanism of particles and cells escaping from optoelectronic tweezer traps

Shuailong Zhang; Aaron R. Wheeler

doi:10.1117/12.2318836

7 September 2018 Hopping mechanism of particles and cells escaping from optoelectronic tweezer traps

Shuailong Zhang, Aaron R. Wheeler

Proceedings Volume 10723, Optical Trapping and Optical Micromanipulation XV; 107231X (2018) https://doi.org/10.1117/12.2318836
Event: SPIE Nanoscience + Engineering, 2018, San Diego, California, United States

Abstract

Optoelectronic tweezers (OET) is an opto-electro-fluidic micromanipulation technology that uses light-induced dielectrophoresis (DEP) for touch-free actuation of micro-scale objects in physical, chemical and biomedical studies. In this work, we introduce a new method to evaluate the behavior of particles trapped in OET traps and used this technique to study their escape mechanism. Particles experiencing negative DEP were made to move in a circular path on a microscope stage, such that the particles’ velocities and trajectories could be observed under different conditions. At high velocities, particles were observed to escape the trap vertically (into the suspending medium) before settling back onto the surface. Three-dimensional numerical simulations of electrical field distribution indicated that the vertical displacement phenomenon occurs when the particle experiences the strongest DEP force at the boundary of the light pattern, lifting the trapped particle to a region where viscous drag exceeds the local horizontal DEP force, thereby forcing it to escape OET confinement. Similar ‘hopping’ phenomena were also observed for cells and particles of different sizes. We propose that the escape mechanism clarified in this work is a general one for objects manipulated by negative DEP in an OET trap, which will be important to consider in the future design of OET-enabled micromanipulation tools for a wide range of applications.

Conference Presentation

Citation Download Citation

Shuailong Zhang and Aaron R. Wheeler "Hopping mechanism of particles and cells escaping from optoelectronic tweezer traps", Proc. SPIE 10723, Optical Trapping and Optical Micromanipulation XV, 107231X (7 September 2018); https://doi.org/10.1117/12.2318836

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available