Providing DEP Manipulation Devices And Controllable Electrowetting Devices In The Same Microfluidic Apparatus

Abstract

A structure for providing a boundary for a chamber in a microfluidic apparatus can comprise dielectrophoresis (DEP) configurations each having an outer surface and electrowetting (EW) configurations each having an electrowetting surface. The DEP configurations can facilitate generating net DEP forces with respect to the outer surfaces of the DEP configurations to move micro-objects on the outer surfaces, and the EW configurations can facilitate changing wetting properties of the electrowetting surfaces to move droplets of liquid medium on the electrowetting surfaces.

We claim: 
     
         1 . A structure comprising:
 a dielectrophoresis (DEP) configuration comprising an outer surface; and   an electrowetting (EW) configuration comprising an electrowetting surface,   wherein said DEP configuration is disposed adjacent to said EW configuration such that said outer surface of said DEP configuration is adjacent to said electrowetting surface.   
     
     
         2 . The structure of  claim 1 , wherein said DEP configuration comprises:
 a first electrode; and   a switchable element disposed between said outer surface and said first electrode,   wherein said switchable element is configured to temporarily create an electrically conductive first path from a first region of said outer surface through said switchable element to said first electrode.   
     
     
         3 . The structure of  claim 2 , wherein said EW configuration comprises:
 a second electrode,   a dielectric layer disposed between said electrowetting surface and said second electrode, and   a switchable element disposed between said dielectric layer and said second electrode,   wherein said switchable element is configured to temporarily create an electrically conductive second path through said switchable element and thereby change a wetting property of a second region of said electrowetting surface adjacent to said path.   
     
     
         4 . The structure of  claim 3 , wherein:
 said switchable element of said DEP configuration comprises a photoconductive material, and   selectively illuminating a portion of said photoconductive material adjacent to said first region reduces an impedance of said portion creating said first path.   
     
     
         5 . The structure of  claim 3 , wherein said switchable element of said DEP configuration comprises a switch from said first region of said outer surface through said switchable element to said first electrode. 
     
     
         6 . The structure of  claim 5 , wherein said switch is light activated. 
     
     
         7 . The structure of  claim 5 , wherein said switch comprises a transistor embedded in said switchable element. 
     
     
         8 . The structure of  claim 5 , wherein said switchable element further comprises isolation barriers in said switchable element about said switch. 
     
     
         9 . The structure of  claim 8 , wherein said switchable element of said EW configuration comprises photoconductive material disposed in said isolation barriers. 
     
     
         10 . The structure of  claim 3 , wherein said outer surface of said DEP configuration is substantially parallel to said electrowetting surface of said EW configuration. 
     
     
         11 . The structure of  claim 10  further comprising a monolithic component, wherein:
 a first section of said monolithic component comprises said switchable element of said DEP configuration, and 
 a second section of said monolithic component comprises said switchable element of said EW configuration. 
 
     
     
         12 . The structure of  claim 10  further comprising a support structure, wherein:
 a first section of said support structure comprises said switchable element of said EW configuration, and 
 said EW configuration is disposed in a cavity in a second section of said support structure adjacent to said first section. 
 
     
     
         13 . The structure of  claim 1 , wherein:
 said DEP configuration is a first distinct device, and   said EW configuration is a second distinct device disposed adjacent to said DEP configuration, and   said outer surface of said DEP configuration is substantially parallel to said electrowetting surface of said EW configuration.   
     
     
         14 . The structure of  claim 1 , wherein said EW configuration comprises:
 a first electrode,   a dielectric layer disposed between said electrowetting surface and said first electrode, and   a switchable element disposed between said dielectric layer and said first electrode,   wherein said switchable element is configured to temporarily create an electrically conductive path through said switchable element and thereby change a wetting property of a region of said electrowetting surface adjacent to said path.   
     
     
         15 . The structure of  claim 14 , wherein said switchable element of said EW configuration comprises a photoconductive material. 
     
     
         16 . The structure of  claim 14 , wherein said switchable element of said EW configuration comprises a switch through said switchable element to said first electrode. 
     
     
         17 . The structure of  claim 1 , wherein said outer surface of said DEP configuration and said electrowetting surface of said EW configuration are substantially parallel. 
     
     
         18 . The structure of  claim 17 , wherein said outer surface of said DEP configuration and said electrowetting surface of said EW configuration are substantially in a same plane. 
     
     
         19 . The structure of  claim 17 , wherein said outer surface of said DEP configuration and said electrowetting surface of said EW configuration form a substantially continuous composite surface. 
     
     
         20 . The structure of  claim 1  further comprises:
 a plurality of said DEP configurations each comprising an outer surface, and 
 a plurality of said EW configurations each comprising an electrowetting surface, 
 wherein at least some of said DEP configurations and said EW configurations are disposed such that said outer surfaces and said electrowetting surfaces are in alternating patterns. 
 
     
     
         21 . The structure of  claim 20 , wherein said outer surfaces of said DEP configurations and said electrowetting surfaces of said EW configurations are substantially in a same plane. 
     
     
         22 . The structure of  claim 20 , wherein said outer surfaces of said DEP configurations and said electrowetting surfaces of said EW configurations form a substantially continuous composite surface. 
     
     
         23 . The structure of  claim 20 , wherein:
 said outer surfaces of said DEP configurations are hydrophilic, and   said electrowetting surfaces of said EW configurations are hydrophobic.   
     
     
         24 . A process of operating a microfluidic apparatus comprising a chamber, dielectrophoresis (DEP) devices, and electrowetting (EW) devices, said process comprising:
 moving a micro-object from a first outer surface of a first of said DEP devices to a second surface of a second of said DEP devices by activating said second DEP device and thereby creating a net DEP force on said micro-object in a direction of said second DEP device; and   moving a droplet of a liquid medium from a first location to a second location in said chamber by activating a second of said EW devices and thereby changing a wetting property of a second electrowetting surface of said second EW device,   wherein:
 in said first location said droplet is disposed in part on a first electrowetting surface of a first of said EW devices but not on said second electrowetting surface of said second EW device, and 
 in said second location said droplet is disposed in part on said second electrowetting surface of said second EW device but not on said first electrowetting surface of said first EW device. 
   
     
     
         25 . The process of  claim 24 , wherein said moving said droplet comprises moving part of said droplet over an outer surface of one of said DEP devices disposed between said first EW device and said second EW device. 
     
     
         26 . The process of  claim 25 , wherein:
 said outer surface of said one of said DEP devices is hydrophilic, and   said first electrowetting surface and said second electrowetting surface are hydrophobic.   
     
     
         27 . The process of  claim 26 , wherein said changing said wetting property of said second electrowetting surface comprises temporarily reducing a hydrophobicity of said second electrowetting surface. 
     
     
         28 . The process of  claim 26 , wherein said changing said wetting property of said second electrowetting surface comprises temporarily changing said second electrowetting surface from hydrophobic to hydrophilic. 
     
     
         29 . The process of  claim 24 , wherein said moving said micro-object comprises moving said micro-object from said first outer surface across an electrowetting surface of an adjacent to one of said EW devices to said second outer surface. 
     
     
         30 . The process of  claim 24 , wherein:
 a structural boundary of said chamber comprises said first outer surface, said second outer surface, said first electrowetting surface, and said second electrowetting surface, and   said process further comprises performing both of said moving steps simultaneously.   
     
     
         31 . The process of  claim 24 , wherein:
 a micro-object is disposed in said droplet, and   said moving said droplet further comprises said micro-object moving with said droplet.   
     
     
         32 . A process of manipulating a droplet of liquid medium in a microfluidic apparatus comprising a chamber, dielectrophoresis (DEP) devices, and electrowetting (EW) devices, said process comprising:
 disposing a droplet of a first liquid medium on first outer surfaces of a first set of said DEP devices and first electrowetting surfaces of a first set of said EW devices;   separating a first part of said droplet from a second part of said droplet by activating second electrowetting surfaces of a second set of said EW devices and thereby changing a wetting property of said second electrowetting surfaces.   
     
     
         33 . The process of  claim 32 , wherein said separating comprises moving said first part of said droplet from a first location comprising said first outer surfaces of said first DEP devices and said first electrowetting surfaces of said first EW devices to a second location comprising second outer surfaces of a second set of said DEP devices and said second electrowetting surfaces of said second set of said EW devices. 
     
     
         34 . The process of  claim 33 , wherein said separating comprises:
 activating third electrowetting surfaces of a third set of said EW devices disposed between said first set of said EW devices and said second set of said EW devices, and   thereafter activating said second electrowetting surfaces of said second set of EW devices.   
     
     
         35 . The process of  claim 34 , wherein:
 none of said DEP devices in said second set of DEP devices is also in said first set of DEP devices,   none of said EW devices in said second set of EW devices is also in said first set of EW devices or said third set of EW devices, and   none of said EW devices in said EW devices in said first set of EW devices is also in said third set of EW devices.   
     
     
         36 . The process of  claim 34 , wherein said second location is separated from and does not overlap said first location. 
     
     
         37 . The process of  claim 33 , wherein said separating said first part of said droplet comprises a first group of micro-objects disposed in said first part of said droplet moving with said first part of said droplet from said first location to said second location. 
     
     
         38 . The process of  claim 33  further comprising, prior to said separating said first part of said droplet, selecting said first group of micro-objects from a larger group of micro-objects in said droplet.