University of Southampton

Collin Sones

Robert Eason

Ioannis Katis

Peijun He

Techniques for making fluid flow devices are described. The technique is based on radiation-induced conversion of a radiation-sensitive substance from a first state to a second state. With adjustment of the radiation parameters such as power and scan speed we can control the depths of barriers that are formed within a substrate which can produce 3D flow paths. We have used this depth-variable patterning protocol for stacking and sealing of multilayer substrates, for assembly of backing layers for two-dimensional (2D) lateral flow devices and for fabrication of 3D devices. Since the 3D flow paths can be formed via a single laser-writing process by controlling the patterning parameters, this is a distinct improvement over other methods that require multiple complicated and repetitive assembly procedures.

Fluid flow device and method for making the same

A method of making a fluid flow device comprises providing a substrate of porous material, depositing a radiation-sensitive substance onto the substrate in a pattern defining one or more regions intended to receive and contain fluid during use of the device or occupying an area within such a region, such that the radiation-sensitive substance extends at least partly through the thickness of the substrate below the pattern, and exposing radiation onto the substrate thereby delivering energy to the radiation-sensitive substance in at least part of the pattern to change the radiation-sensitive substance from a first state to a second state through at least part of the thickness of the substrate. One of the first state and the second state may be less permeable than the other.

Fluid flow device on a porous substrate and method for making the same

A method of making a fluid flow device comprises: providing a substrate of porous material () impregnated with a light-sensitive substance () in a first state and which is configured to change from the first state to a second state when exposed to light (), the second state being a solid state that is resistant to a solvent and the first being removable with the solvent; the substrate having a fluid flow channel () defined therein, the channel having a depth; exposing a beam of light () onto an area of the substrate surface within the fluid flow channel to deliver energy to a volume of the substrate below the area to change the light-sensitive substance to the second state; during exposure, creating a partial barrier to flow of fluid along the channel by controlling the amount of energy delivered to the volume below at least part of the area to change the light-sensitive substance to the second state in a volume of the substrate within the fluid flow channel that has a depth less than the depth of the fluid flow channel; and developing the substrate in the solvent to leave the light-sensitive substance which is in the solid state and remove the light-sensitive substance which is in the other state. The device may be a medical diagnostic device, and the substrate may be a paper substrate or may be a nitrocellulose substrate.

Growing community of inventors

Southampton, United Kingdom

Collin Sones