# US 7,612,355 B2 · Optoelectronic tweezers for microparticle and cell manipulation

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- Number: US 7,612,355 B2
- Document ID: US7612355B2
- Status: Granted
- Kind: B2
- Application number: 11/105,304
- Filed: 2005-04-12
- Published: 2009-07-02
- Granted: 2009-11-03
- Earliest claimed: 2004-04-12
- Assignees: The Regents of the University of California
- Inventors: Ming Chiang Wu; Pei Yu Chiou; Aaron T. Ohta
- Web page: https://patentgrep.com/patent/US7612355B2

## CPC

- B03C 5/026: {using open-gradient differential dielectric separation, i.e. using electrodes of special shapes for non-uniform field creation, e.g. Fluid Integrated Circuit [FIC]}
- B01L 3/502761: {specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads or physically stretching molecules}
- B01L 2400/0454: radiation pressure, optical tweezers
- G01N 2035/1046: {Levitated, suspended drops}
- B03C: MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS (separating isotopes B01D59/00; combinations of magnetic or electrostatic separation with separation of solids by other means B03B, B07B)
- B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

An optical image-driven light induced dielectrophoresis (DEP) apparatus and method are described which provide for the manipulation of particles or cells with a diameter on the order of 100 μm or less. The apparatus is referred to as optoelectric tweezers (OET) and provides a number of advantages over conventional optical tweezers, in particular the ability to perform operations in parallel and over a large area without damage to living cells. The OET device generally comprises a planar liquid-filled structure having one or more portions which are photoconductive to convert incoming light to a change in the electric field pattern. The light patterns are dynamically generated to provide a number of manipulation structures that can manipulate single particles and cells or groups of particles/cells. The OET preferably includes a microscopic imaging means to provide feedback for the optical manipulation, such as detecting position and characteristics wherein the light patterns are modulated accordingly.

## Claims

### Claim 1

An apparatus for manipulating cells or particles by light induced dielectrophoresis (DEP), the apparatus comprising:
a first surface and a second surface configured for retaining a liquid comprising particles or cells to be manipulated;
at least one photoconductive area on said first or said second surface configured for conversion of received light to a local electric field in the vicinity of the received light;
a light source to provide the light received by the photoconductive area;
wherein the local electric field selectively repels or attracts particles or cells;
a microvision-based pattern recognition subsystem which is configured for controlling the output of said light source in response to registering the position of, and optionally the characteristics of, particles or cells as determined from microscopic imaging.

### Claim 2 (depends on 1)

An apparatus as recited in claim 1, wherein said characteristics are selected from the group of particle and cell characteristics consisting essentially of size, color, shape, texture, viability, motility, conductivity, permeability, capacitance and response to changes in the environment of the particle or cell.

### Claim 3

An apparatus for manipulating cells and particles using optical image-driven light induced dielectrophoresis (DEP) over a two-dimensional area, comprising:
a first surface and second surface configured for retaining a liquid containing particles, or cells to be manipulated;
at least one photoconductive area on said first or second surface which is configured for inducing a local electric field, virtual electrode, in the vicinity of received light;
an optical projector or scanning laser configured for generating dynamic sequential two-dimensional light patterns onto said photosensitive surface thereby inducing dynamic localized electric fields for DEP manipulation of particles or cells; and
a microscopic imaging subsystem which is configured for controlling the output of said optical projector in response to registering the position of, and optionally the characteristics of, particles or cells as determined from analyzing microscopic images.

### Claim 4 (depends on 3)

An apparatus as recited in claim 3, wherein said characteristics are selected from the group of particle and cell characteristics consisting essentially of size, color, shape, texture, viability, motility, conductivity, permeability, capacitance and response to changes in the environment of the particle or cell.