Abstract: An actuator is described, including a first sheet comprising a plurality of first openings,; and a second sheet comprising a plurality of second openings; wherein the first and second sheets are stacked together such that at least one of the first and second openings are misaligned; and the actuator is configured to move from a first state to a second state, wherein in the first state, out-of-plane motion of the first and second sheets is permitted; and in the second state, the first and second sheets as well as the misaligned first and second openings are jammed together to restrict the out-of-plane motion of the first and second sheets. Methods of actuating and making such actuator are also described.

Abstract: An additive manufacturing extruder includes a melt chamber with a heat source, having a first inlet for receiving a first extrudable material and a second inlet for receiving a second extrudable material, and an interior channel leading to an outlet leading to a nozzle; and a intermixer associated with the outlet or the nozzle. The intermixer directs flow of the extrudable materials to produce a mechanically keyed extrudate.