Design and fabrication of a digitally reconfigurable surface

Abstract

The digitally reconfigurable surface is a pin based mechanism for creating physical threedimensional contoured surfaces from a computer aided design (CAD) input. When the digital design is properly downloaded into the device, a pin array is collectively actuated to the desired geometry. A rubber interpolation layer is held onto the tops of the pins by vacuum pressure to prevent undesired dimpling of the surface caused by the discrete nature of the pin array. Prior art in this field of reconfigurable pin tooling (RPT) surfaces have mostly involved using large diameter pins with conventional linear actuators behind each pin. Such devices have rarely been commercially viable as the surface area and resolution of the surface scales poorly with the number of actuators and cost. The digitally reconfigurable surface developed theoretically only requires a single mechanically actuated plate, regardless of scale or resolution (number of pins or diameter of pins). The device works by pulling all of the closely packed steel pins simultaneously in one direction via a magnetic moving plate, and as they move, pins are individually clutched and held in position by a novel fusible alloy clutch array, integrated with input circuitry. When the magnetic plate reaches the end of its stroke, all pins are in the proper configuration. The simplicity of this actuation method allows for improved scalability (resolution and area) and low manufacturing cost for the device. In addition, the phase changing clutch array, when coupled with notched or threaded pins, has an excellent holding strength allowing for many possible high pressure molding applications on surfaces generated. It is my hope that this research will one day pave the way for a practical, commercially available, reconfigurable pin-based forming tool.