Method and apparatus for manipulating single cells and small aggregates thereof

1. A structure including at least one microwell and a channel, the at least one microwell comprising:

a dielectric material forming at least one lateral wall that delimits the at least one microwell and extends between an upper end and a lower end, the at least one microwell open at the upper and open at the lower end, the at least one microwell configured to retain a first volume of a liquid and particles contained within the liquid, such that the first volume of the liquid forms a meniscus at one of the upper end and the lower end when retained in the at least one microwell; and

at least two manipulation electrodes within the dielectric material such that each manipulation electrode at least partially defines the at least one lateral wall, the manipulation electrodes able to be powered by electrical voltages so as to produce dielectrophoretic manipulation of particles in the at least one microwell;

wherein the channel includes an inlet and an outlet and is configured to allow at least a second volume of the liquid to flow from the inlet to the outlet, and wherein an axis extending from the inlet to the outlet, along the direction of liquid flow within the channel, is oriented perpendicularly to a central axis of symmetry of the well, the central axis of symmetry extending from the upper end to the lower end, and wherein the channel is in direct fluid communication with the one of the upper end and the lower end of the at least one microwell that is opposite the end at which the meniscus forms, and wherein the channel is configured such that the liquid may flow directly between the channel and the microwell.

2. The structure of claim 1 , wherein the meniscus is disposed at the upper end of the at least one microwell, and wherein the channel is disposed at the lower end of the at least one microwell.

3. The structure of claim 1 , wherein the manipulation electrodes comprise plates of conducting material substantially disposed in different planes transverse to the central axis of symmetry of the at least one microwell.

4. The structure of claim 1 , wherein the manipulation electrodes face each other across a lateral wall delimiting the at least one microwell, the lateral wall comprising a dielectric material in which the manipulation electrodes are embedded.

5. The structure of claim 1 , wherein the lateral wall delimiting the at least one microwell has a hydrophilic surface.

6. The structure of claim 1 , wherein the lateral wall delimiting the at least one microwell has a hydrophobic surface.

7. The structure of claim 1 , wherein a wall external to the at least one microwell and adjacent to the at least one microwell lateral wall has a hydrophilic surface and the at least one microwell lateral wall has a hydrophobic surface; or the wall external to the at least one microwell and adjacent to the at least one microwell lateral wall has a hydrophobic surface and the at least one microwell lateral wall has a hydrophilic surface.

8. The structure of claim 1 , wherein at least one of the manipulation electrodes forms an annular rim along the delimiting wall of the at least one microwell, the rim being disposed substantially in a plane transverse to the central axis of symmetry of the at least one microwell.

9. The structure of claim 8 , wherein the at least one microwell includes at least three electrodes disposed in parallel planes, forming the annular rim.

10. The structure of claim 1 , further comprising at least one pair of electrodes disposed in the same plane transverse to the central axis of symmetry of the at least one microwell, forming two annular rim portions along the delimiting wall of the at least one microwell separated from each other by a surface parallel to the central axis of symmetry of the at least one microwell.

11. The structure of claim 10 , further comprising an electrode forming a second annular rim disposed in a different transverse plane than the pair of electrodes, the second annular rim disposed towards the upper end of the at least one microwell with respect to the pair of electrodes.

12. The structure of claim 10 , comprising two pairs of electrodes disposed in two different planes transverse to the central axis of symmetry of the at least one microwell.

13. The structure of claim 1 , further comprising sensors for measuring physical and/or chemical characteristics of at least one microwell contents, wherein the sensors are of impedimetric, optical or potentiometric type.

14. The structure of claim 13 wherein the sensors of impedimetric type comprise a pair of measurement electrodes configured to measure impedance, the measurement electrodes suitable for displacing particles contained in the at least one microwell and/or to induce electroporation or fusion reactions if suitably powered.

15. The structure of claim 1 , wherein the meniscus is disposed at the lower end of the at least one microwell, and wherein the channel is disposed at the upper end of the at least one microwell.

16. The structure of claim 1 , wherein at least one of the manipulation electrodes is able to also function as a sensor.

17. The structure of claim 1 comprising a plurality of channels, each of the channels coupled to a plurality of microwells.