Air-matrix digital microfluidics apparatuses and methods for limiting evaporation and surface fouling

• US 10,464,067 B2
• Filed: 06/06/2016
• Issued: 11/05/2019
• Est. Priority Date: 06/05/2015
• Status: Active Grant

• Current Assignee: Miroculus Inc.
• Original Assignee: Miroculus Inc.
• Inventors: Jebrail, Mais J., Barbulovic-Nad, Irena, Gutierrez, Lorenzo, Christodoulou, Foteini
• Primary Examiner(s): Wecker, Jennifer
• Application Number:
  US15/579,455
• Publication Number:
  US 20180141049A1
• Time in Patent Office: 1,247 Days
• CPC Class Codes: B01L 2200/027 for microfluidic devices
• CPC Class Codes: B01L 2200/142 Preventing evaporation
• CPC Class Codes: B01L 2300/042 Caps; Plugs
• CPC Class Codes: B01L 2300/0874 Three dimensional network
• CPC Class Codes: B01L 2300/18 Means for temperature control
• CPC Class Codes: B01L 2300/1822 using Peltier elements
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0427 Electrowetting
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: C12M 23/16 Microfluidic devices; Capillary tubes integrated microfluidic structures B01L3/5027; microreactors B01J19/0093
• CPC Class Codes: G01N 27/44791 Microapparatus sample containers with integrated microfluidic structures B01L3/5027

Abstract

Air-matrix digital microfluidics (DMF) apparatuses and methods of using them to prevent or limit evaporation and surface fouling of the DMF apparatus. In particular, described herein are air-matrix DMF apparatuses and methods of using them in which a separate well that is accessible from the air gap of the DMF apparatus isolates a reaction droplet by including a cover to prevent evaporation. The cover may be a lid or cap, or it may be an oil or wax material within the well. The opening into the well and/or the well itself may include actuation electrodes to allow the droplet to be placed into, and in some cases removed from, the well. Also described herein are air-matrix DMF apparatuses and methods of using them including thermally controllable regions with a wax material that may be used to selectively encapsulate a reaction droplet in the air gap of the apparatus.

Claims

1. A method of preventing droplet evaporation within an air-matrix digital microfluidic (DMF) apparatus, the method comprising:

introducing a reaction droplet into an air gap of the air-matrix DMF apparatus which is formed between a first plate and a second plate of the air-matrix DMF apparatus;

combining the reaction droplet with a liquid wax material that is present at a predetermined location within the air-matrix DMF apparatus to protect the reaction droplet from evaporation; and

allowing a reaction to proceed within the reaction droplet.

2. The method of claim 1, further comprising introducing the liquid wax material at the predetermined location within the air-matrix DMF apparatus.

3. The method of claim 2, wherein introducing comprises melting a solid wax material to form the liquid wax material by increasing the temperature of a portion of the air gap comprising a thermal zone to a temperature above the melting point of the wax material.

4. The method of claim 3, wherein melting the solid wax material comprises melting a solid wax body formed into a wall or open chamber within the air gap.

5. The method of claim 1, wherein introducing the reaction droplet into an air gap comprises combining multiple droplets to form the reaction droplet within the air gap.

6. The method of claim 3, wherein the first plate comprises a plurality of adjacent actuation electrodes, and wherein combining the reaction droplet with the liquid wax material comprises applying energy to a subset of the plurality of adjacent actuation electrodes to move the reaction droplet in contact with the solid wax material prior to melting the solid wax material.

7. The method of claim 1, wherein the first plate comprises a plurality of adjacent actuation electrodes, and wherein combining the reaction droplet with the liquid wax material comprises applying energy to a subset of the plurality of adjacent actuation electrodes to move the reaction droplet in contact with the liquid wax material.

8. The method of claim 1, wherein allowing a reaction to proceed comprises heating portion of the air gap containing the reaction droplet.

9. The method of claim 1, further comprising detecting a product within the reaction droplet.

10. The method of claim 1, further comprising moving the reaction droplet coated with the liquid wax material within the air gap.

11. A method of preventing droplet evaporation within an air-matrix digital microfluidic (DMF) apparatus, the method comprising:

introducing a reaction droplet into an air gap of the air-matrix DMF apparatus which is formed between a first plate and a second plate of the air-matrix DMF apparatus;

introducing a liquid wax material at the predetermined location within the air-matrix DMF apparatus;

combining the reaction droplet with the liquid wax material at the predetermined location within the air-matrix DMF apparatus to protect the reaction droplet from evaporation; and

allowing a reaction to proceed within the reaction droplet.

12. The method of claim 11, wherein introducing the liquid wax material comprises melting a solid wax material to form the liquid wax material by increasing the temperature of a portion of the air gap comprising a thermal zone to a temperature above the melting point of the wax material.

13. The method of claim 12, wherein melting the solid wax material comprises melting a solid wax body formed into a wall or open chamber within the air gap.

14. The method of claim 11, wherein introducing the reaction droplet into the air gap comprises combining multiple droplets to form the reaction droplet within the air gap.

15. The method of claim 12, wherein the first plate comprises a plurality of adjacent actuation electrodes, and wherein combining the reaction droplet with the liquid wax material comprises applying energy to a subset of the plurality of adjacent actuation electrodes to move the reaction droplet in contact with the solid wax material prior to melting the solid wax material.

16. The method of claim 11, wherein the first plate comprises a plurality of adjacent actuation electrodes, and wherein combining the reaction droplet with the liquid wax material comprises applying energy to a subset of the plurality of adjacent actuation electrodes to move the reaction droplet in contact with the liquid wax material.

17. The method of claim 11, wherein allowing a reaction to proceed comprises heating a portion of the air gap containing the reaction droplet.

18. The method of claim 11, further comprising detecting a product within the reaction droplet.

19. A method of preventing droplet evaporation within an air-matrix digital microfluidic (DMF) apparatus, the method comprising:

introducing a reaction droplet into an air gap of the air-matrix DMF apparatus which is formed between a first plate and a second plate of the air-matrix DMF apparatus;

introducing a liquid wax material at the predetermined location within the air-matrix DMF apparatus;

combining the reaction droplet with the liquid wax material at the predetermined location within the air-matrix DMF apparatus to protect the reaction droplet from evaporation;

moving the reaction droplet coated with the liquid wax material within the air gap; and

allowing a reaction to proceed within the reaction droplet.