US 11,865,535 B2
Microfluidic reaction system
Rachel M. White, Corvallis, OR (US); and Uranbileg Daalkhaijav, Corvallis, OR (US)
Assigned to Hewlett-Packard Development Company, L.P., Spring, TX (US)
Appl. No. 16/493,694
Filed by HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P., Spring, TX (US)
PCT Filed Jul. 28, 2017, PCT No. PCT/US2017/044543
§ 371(c)(1), (2) Date Sep. 12, 2019,
PCT Pub. No. WO2018/194700, PCT Pub. Date Oct. 25, 2018.
Claims priority of application No. PCT/US2017/028574 (WO), filed on Apr. 20, 2017; and application No. PCT/US2017/028586 (WO), filed on Apr. 20, 2017.
Prior Publication US 2020/0023355 A1, Jan. 23, 2020
Int. Cl. B01L 3/00 (2006.01); B81B 7/00 (2006.01)
CPC B01L 3/5027 (2013.01) [B81B 7/00 (2013.01); B01L 2200/16 (2013.01); B01L 2300/0645 (2013.01); B01L 2300/1827 (2013.01); B01L 2400/0442 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A microfluidic reaction system comprising
a microfluidic die comprising a microfluidic volume comprising a microfluidic channel having a dimension on an order of 10 microns;
a proud structure rising from a floor of the microfluidic volume;
a port connected to the microfluidic volume for receiving a fluid; and
a freeze-dried reaction agent, wherein external surfaces of the proud structure that face the microfluidic volume are coated with the freeze-dried reaction agent.
 
16. A method of making the microfluidic reaction system of claim 1, the method comprising:
forming a microfluidic volume in a microfluidic die;
forming a proud structure rising from a floor of the microfluidic volume;
introducing a reaction agent into the microfluidic volume; and
freeze-drying the reaction agent within the microfluidic volume to coat external surfaces of the proud structure that face the microfluidic volume, the freeze-drying comprising:
freezing the reaction agent during a first freezing period; and
drying the reaction agent during two drying periods, a first drying period having a lower temperature than a second drying period.