High throughput screening of crystallization of materials

A method of capturing a concentration gradient between two fluids, the method comprising:

• providing a first fluid on a first side of an elastomer membrane present within a microfluidic flow channel;
• providing a second fluid on a second side of the elastomer membrane;
• displacing the elastomer membrane from the microfluidic flow channel to define a microfluidic free interface between the first fluid and the second fluid;
• allowing the first fluid and the second fluid to diffuse across the microfluidic free interface;
• and
• actuating a group of elastomer valves positioned along the flow channel at increasing distances from the microfluidic free interface to define a succession of chambers whose relative concentration of the first fluid and the second fluid reflects a time of diffusion.

A method for forming crystals of a target material comprising:

• priming a first chamber of an elastomeric microfluidic device with a first predetermined volume of a target material solution;
• priming a second chamber of an elastomer micro fluidic device with a second predetermined volume of a crystallizing agent solution;
• and
• placing the first chamber into fluidic contact with the second chamber to allow free-interface diffusion between the target material and the crystallizing agent solution, such that an environment of the target material is changed to cause formation of crystal.