Confinement and deposition of solution droplets on solvophilic surfaces using a flat high surface energy guide

A method of depositing small amounts of solution on flat micron scale surface areas on a hydrophilic substrate or die was developed. This method utilizes the capillarity of a flat, high surface free energy guide. Interfacial forces confine the solution between the guide and the substrate surface. The liquid follows the movement of the guide along the surface and can be moved to the desired area. The thermodynamic background of the method is given and its application to coat one arm of a gold plasmonic Mach-Zehnder interferometer with bovine serum albumin is described. This method, which is related to but different from microcontact printing and dip-pen microlithography, can be utilized in the manufacturing of biosensors and other lab-on-a-chip structures, and is particularly suitable to development stage devices.