Stop-start method in a microfluidic calorimeter

Patent metadata

Field	Value
Publication number	US-10677661-B2
Application number	US-201715805650-A
Country	US
Kind code	B2
Filing date	Nov 7, 2017
Priority date	Nov 9, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A method for calorimetry includes flowing a first fluid through a co-flow reactor microchannel having plural inlets and an outlet, the first fluid flowing through each of the inlets, and measuring transmission of light through a Nano Hole Array (NHA) sensor to obtain a baseline extraordinary optical transmission (EOT) measurement. The flow of the first fluid is stopped, the microchannel is emptied of the first fluid, and the first fluid and a second fluid are passed through the microchannel such that a reaction occurs, the first fluid flowing through a first of the inlets and the second fluid flowing through a second of the inlets. While flowing the first and second fluids, transmission of light through the NHA sensor is measured to obtain a reaction EOT measurement. A calorimetry measurement, indicative of energy released during the reaction, is calculated as a function of the baseline and reaction EOT measurements.

First claim

What is claimed is:

1. A method for calorimetry, the method comprising:
a) flowing a first fluid through a co-flow reactor microchannel having plural inlets and an outlet, the first fluid flowing through each of the inlets;
b) while flowing the first fluid, measuring transmission of light through a Nano Hole Array (NHA) sensor coupled to the co-flow reactor micro channel, to obtain a baseline extraordinary optical transmission (EOT) measurement;
c) stopping the flow of the first fluid;
d) emptying the co-flow reactor microchannel of the first fluid after stopping the flow of the first fluid;
e) flowing the first fluid and a second fluid through the co-flow reactor microchannel such that a reaction occurs at least at a diffusion interface of the fluids, the first fluid flowing through a first of the inlets and the second fluid flowing through a second of the inlets;
f) while flowing the first and second fluids, measuring transmission of light through the NHA sensor to obtain a reaction EOT measurement; and
g) calculating a calorimetry measurement as a function of the baseline EOT measurement and the reaction EOT measurement, the calorimetry measurement being indicative of energy released during the reaction, wherein calculating the calorimetric measurement includes averaging the EOT measurements over a period of time to obtain an averaged baseline EOT value and an averaged reaction EOT value.

2. The method of claim 1 , wherein flowing the first and seconds fluids includes using a syringe pump to drive the first fluid from a first syringe coupled to the first of the inlets and drive the second fluid from a second syringe coupled the second of the inlets.

3. The method of claim 1 , wherein emptying the co-flow reactor microchannel includes applying a vacuum source to the microchannel.

4. The method of claim 1 , wherein measuring transmission of light includes irradiating the NHA sensor and fluid flowing through the co-flow reactor microchannel with incident light.

5. The method of claim 1 , wherein the NHA sensor includes an array of holes in an electrically conducting layer, the layer being proximate to and in thermal contact with the co-flow reactor microchannel.

6. The method of claim 1 , wherein stopping the flow of the first fluid and emptying the co-flow reactor microchannel reduces formation of bubbles when flowing the first and second fluids through the co-flow reactor microchannel.

7. The method of claim 1 , wherein calculating the calorimetric measurement includes calculating an EOT difference by subtracting the averaged reaction EOT value from the averaged baseline EOT value.

8. The method of claim 7 , wherein the EOT difference is calculated for multiple NHA sensors that are equally spaced apart.

9. The method of claim 8 , wherein the NHA sensors are arranged in parallel rows that are transverse to a direction of flow through the co-flow reactor microchannel.

10. The method of claim 1 , wherein the first and second fluids comprise dielectric materials.

11. The method of claim 10 , wherein the second fluid includes a carrier fluid and a reactant.

12. The method of claim 11 , wherein the first fluid includes a carrier fluid and a reactant that is different from the reactant of the second fluid.

13. The method of claim 12 , wherein the carrier fluids of the first and second fluids are the same.

14. A system for calorimetry, the system comprising:
a) a co-flow reactor microchannel having plural inlets and an outlet;
b) multiple Nano Hole Array (NHA) sensors equally spaced apart and coupled to the co-flow reactor microchannel;
c) a pump to drive fluid through the co-flow reactor microchannel;
d) a vacuum source coupled to the microchannel; and
e) a controller coupled to the pump and the NHA sensors, the controller programmed to:
i) control the pump to flow a first fluid through a co-flow reactor microchannel, the first fluid flowing through each of the inlets;
ii) while flowing the first fluid, measure transmission of light through the NHA sensors to obtain a baseline extraordinary optical transmission (EOT) measurement;
iii) control the pump to stop the flow of the first fluid;
iv) control the vacuum source to empty the co-flow reactor microchannel of the first fluid after stopping the flow of the first fluid;
v) control the pump to flow the first fluid and a second fluid through the co-flow reactor microchannel such that a reaction occurs at least at a diffusion interface of the fluids, the first fluid flowing through a first of the inlets and the second fluid flowing through a second of the inlets;
vi) while flowing the first and second fluids, measure transmission of light through the NHA sensors to obtain a reaction EOT measurement; and
vii) calculate a calorimetry measurement as a function of the baseline EOT measurement and the reaction EOT measurement, the calorimetry measurement being indicative of energy released during the reaction, the calorimetric measurement including an EOT difference calculated for the NHA sensors.

15. The system of claim 14 , wherein the pump is a syringe pump configured to drive the first fluid from a first syringe coupled to the first of the inlets and, when flowing the first and second fluids, drive the second fluid from a second syringe coupled the second of the inlets.

16. The system of claim 14 , further including a light source configured to irradiate the NHA sensor and fluid flowing through the co-flow reactor microchannel, wherein the controller is programmed to control the light source to irradiate the NHA sensor and fluid flowing through the co-flow reactor microchannel with incident light to measure the transmission of light.

17. The system of claim 14 , wherein the NHA sensor includes an array of holes in an electrically conducting layer, the layer being proximate to and in thermal contact with the co-flow reactor microchannel.

18. The system of claim 14 , wherein the NHA sensors are arranged in parallel rows that are transverse to a direction of flow through the co-flow reactor microchannel.

Assignees

• Univ Northeastern

Inventors

• Modaresifar Masoud
• Kowalski Gregory J

Classifications

• G01N25/4873

  for a flowing, e.g. gas sample · CPC title

• G01K11/32 Primary

  using changes in transmittance, scattering or luminescence in optical fibres · CPC title

• B01L3/502

  with fluid transport, e.g. in multi-compartment structures · CPC title

• G01K17/006 Primary

  Microcalorimeters, e.g. using silicon microstructures · CPC title