	US 12,203,840 B2
	Apparatus for transmission optical measurements with a window in an opaque substrate
Sam Hyde, Royston (GB); Alex Zhukov, Royston (GB); Robyn Pritchard, Royston (GB); Gang Xiong, Royston (GB); and Samson Rogers, Royston (GB)
Assigned to Cellular Highways Ltd., Royston (GB)
Appl. No. 18/019,528
Filed by Cellular Highways Ltd., Royston (GB)
PCT Filed Aug. 5, 2021, PCT No. PCT/EP2021/071871 § 371(c)(1), (2) Date Feb. 3, 2023, PCT Pub. No. WO2022/029229, PCT Pub. Date Feb. 10, 2022.
Claims priority of application No. 20189934 (EP), filed on Aug. 6, 2020.
Prior Publication US 2023/0288315 A1, Sep. 14, 2023
Int. Cl. G01N 15/14 (2024.01); G01N 15/1434 (2024.01)

CPC G01N 15/1484 (2013.01) [G01N 15/1434 (2013.01); G01N 2015/1452 (2013.01)]

20 Claims

1. A method of producing a microfluidic chip for use in flow cytometry, the method comprising:

providing an opaque substrate, a first surface of which is optically smooth for visible light;

providing a continuous transparent layer across said first surface by vapour deposition so as to provide conformal contact between the continuous transparent layer and the first surface of the opaque substrate;

providing a flow channel bounded on a first side by the continuous transparent layer; and

etching an aperture in a second surface of the opaque substrate extending to the first surface of the opaque substrate so as to provide an optical path between said second surface and the flow channel;

wherein the continuous transparent layer is less reactive to etching than the opaque substrate.