Microfluidic Foil Structure for Precision Fluid Metering

The patent replaces complex phototechnical methods with a simple thermal lamination process. A heated die with recesses is pressed against the foil substrate, using thermal and mechanical energy to directly form the three-dimensional contours. This mechanical-thermal approach substitutes the need for expensive photolithography equipment and processes, achieving the same manufacturing precision through a simpler system.

The invention changes the physical parameters of the material during processing by heating the foil above its glass transition temperature, making it pliable and capable of flowing into the recesses of the die. This parameter change allows the material to be shaped at relatively low pressures and temperatures compared to traditional methods, simplifying the manufacturing process while maintaining high precision contours.

The patent replaces expensive phototechnical methods with a thermal lamination process using a heated die. The die, containing the negative of the desired microstructure, is pressed against the heated foil, causing the material to flow and replicate the fine contours. This mechanical replication method achieves sub-micron precision without requiring expensive photolithography equipment, masks, and cleanroom facilities.

The invention utilizes the glass transition of the polymer foil material. By heating the foil above its glass transition temperature, the material transitions from a rigid state to a pliable state, allowing it to flow and conform to the fine features of the die recesses. This phase transition enables the formation of sub-micron structures through a simple thermal-mechanical process rather than expensive phototechnical methods.

The patent merges multiple manufacturing steps into a single lamination operation. The heated die with integrated recesses simultaneously forms all the fluid network channels, chambers, and connections in one pressing action. This eliminates the need for sequential steps such as separate channel formation, chamber creation, and connection establishment, thereby maintaining manufacturing precision while dramatically improving productivity.

The die is pre-formed with the complete negative of the desired fluid network structure, including all channels, chambers, and interconnections. This preliminary preparation of the tool allows all features to be created in a single lamination step, eliminating the need for multiple sequential manufacturing operations and significantly enhancing production efficiency.