Dan S. Reznik, UC-Berkeley, Berkeley, CA, USA

John F. Canny, UC-Berkeley, Berkeley, CA, USA

Active surfaces can manipulate (i.e., translate, rotate) one or more parts in the plane by "displaying" arbitrary forces at a number of points. Many designs have been proposed based on a massively-parallel array of microactuators. For such "pixel-oriented" devices, a large density of microactuators per unit area is required for acceptable force field programmability; the large number and small size of moving parts renders these devices difficult to fabricate, test, and maintain. Here we take a minimalist approach and look for a mechanically simpler, sturdier design, which retains the same manipulation dexterity. Surprisingly, we show that a rigid flat plate is just such a device. Namely, a closed, horizontal motion of the plate can be computed which yields arbitrary frictional forces (averaged over the motion) at one or more points, so that one or more parts can be translated and/or rotated simultaneously and independently. Analysis for both part feeding and part manipulation cases, along with dynamic simulation and experimental results with a prototype of the device are included.