Magnetorheological fluid valve and variable manufacturing mold

A method for use of a variable mold, the method comprising:

• providing a variable mold comprising:
• a plurality of hydraulic pin systems, each pin system comprising:
• a valve in fluid communication with a supply of pressurized fluid;
• a tubing in fluid communication with the valve;
• and
• a pin coupled to the tubing, wherein:
• the pin is configured for displacement from the tubing in response to the supply of the fluid through the valve to the tubing,
• a longitudinal axis of each pin is mutually parallel and arranged in a two-dimensional array;
• and
• each valve is a magnetorheological valve having a magnetic coil and the fluid is a magnetorheological fluid;
• a controller operably coupled to the valves, the controller configured to control a displacement of each pin of the plurality of hydraulic pin systems;
• and
• a temperature control system comprising a temperature control fluid in contact with each of the valves, wherein the magnetorheological fluid and the temperature control fluid are different fluids;
• extending each pin to a predetermined position for that pin;
• applying a current to each magnetic coil to change a viscosity of the magnetorheological fluid within each valve;
• and
• cooling each valve below a melting point of the magnetorheological fluid.