Microstructured polymer devices
A method of manufacturing a device with a planar electrode structure, the method comprising: (a) forming a microfluidic channel on a substrate; (b) applying a primer layer to at least part of the microfluidic channel, (c) applying a conductive liquid to the microfluidic channel, the conductive liquid comprising electrically conductive particles dispersed in a carrier medium, the carrier medium including a solvent; (d) allowing the conductive liquid to flow throughout the microfluidic channel by capillary action to form the planar electrode structure; and (e) evaporating the solvent from the carrier medium, is described. Devices obtainable using the method and their applications are also described.
1. A method of manufacturing a device with a recessed electrode structure, the method comprising:
providing a substrate with a microfluidic channel structure shaped to match the electrode structure;
applying a primer layer to the microfluidic channel structure, thereby forming a primed microfluidic channel structure;
spreading a conductive liquid to the primed microfluidic channel structure, the conductive liquid comprising a carrier medium, and the carrier medium comprising a solvent in which electrically conductive particles are dispersed;
distributing the conductive liquid throughout the microfluidic channel structure by capillary action; and
absorbing the solvent at least partially by the primer layer; and
evaporating remaining solvent from the carrier medium to allow the electrically conductive particles to form the recessed electrode structure.
2. The method according to claim 1 , further comprising after the evaporating:
laminating the substrate with a cap layer to cover at least a part of the electrode structure.
3. The method according to claim 2 , comprising after the laminating:
applying radiation through the cap layer to cure a radiation curable monomer or prepolymer and thus harden the conductive liquid, wherein the carrier medium further comprises the radiation curable monomer or prepolymer.
4. The method according to claim 3 , wherein the radiation curable monomer or prepolymer is curable with visible light.
5. The method according to claim 1 , wherein the solvent is an organic solvent miscible with water.
6. The method according to claim 5 , wherein the carrier medium further comprises water.
7. The method according to claim 5 , wherein the organic solvent is an oxygenated solvent selected from the group consisting of an alcohol, a glycol ether, and a glycol ester.
8. The method according to claim 1 , wherein the primer layer comprises:
an organic polymer; and a porous particulate material, the porous particulate material being dispersed in the organic polymer.
9. The method according to claim 8 , wherein the organic polymer in the primer layer is selected from the group consisting of:
a polymer comprising a vinyl lactam repeating unit;
a cellulose ether;
a polyvinyl alcohol; and
unmodified or modified gelatin.
10. The method according to claim 1 , wherein during the providing, a pad is additionally formed on the substrate in fluid communicating with the microfluidic channel structure, and during the introducing, the conductive liquid is applied to the pad and distributed to the microfluidic channel structure by capillary action.
11. The method according to claim 1 , wherein the substrate is an organic polymer.
12. The method according to claim 1 , wherein the providing the substrate with the microfluidic channel structure is formed by injection moulding.
13. The method according to claim 1 , wherein the applying the primer layer comprises:
introducing a primer liquid to the microfluidic channel structure, the primer liquid comprising a primer carrier medium, and the primer carrier comprising a primer solvent; and
waiting for the primer liquid to flow throughout the microfluidic channel structure by capillary action.
14. The method according to claim 1 , wherein the primer layer comprises a porous particulate material and the primer layer does not include an organic polymer.
15. A device obtained by a method comprising the steps of:
providing a substrate with a microfluidic channel structure shaped to match a recessed electrode structure;
applying a primer layer to the microfluidic channel structure, thereby forming a primed microfluidic channel structure;
spreading a conductive liquid to the primed microfluidic channel structure, the conductive liquid comprising a carrier medium, and the carrier medium comprising a solvent in which electrically conductive particles are dispersed;
distributing the conductive liquid to flow throughout the microfluidic channel structure by capillary action; and
absorbing the solvent at least partially by the primer layer; and
evaporating remaining solvent from the carrier medium to allow the electrically conductive particles to form the recessed electrode structure.