An end-to-end approach to making self-folded 3D surface shapes by uniform heating

Abstract

Abstract-This paper presents an end-to-end approach for creating 3D shapes by self-folding planar sheets activated by uniform heating. These shapes can be used as the mechanical bodies of robots. The input to this process is a 3D geometry (e.g. an OBJ file). The output is a physical object with the specified geometry. We describe an algorithm pipeline that (1) identifies the overall geometry of the input, (2) computes a crease pattern that causes the sheet to self-fold into the desired 3D geometry when activated by uniform heating, (3) automatically generates the design of a 2D sheet with the desired pattern and (4) automatically generates the design files required to fabricate the 2D structure. We demonstrate these algorithms by applying them to complex 3D shapes. We demonstrate the fabrication of a self-folding object with over 50 faces from automatically generated design files.

Pouch Motors: Printable Soft Actuators Integrated with Computational Design

“…[26][27][28] We modified the algorithm for self-folding sheets 29 to output a 2D unfolded structure for later process. We transform the 3D model as a graph and unfold it using Prim's algorithm (a minimum spanning tree algorithm).…”

Impressions of Size-Changing in a Companion Robot

“…The need for adaptive companion robots has been voiced (Dautenhahn, 2004). Already, simple size changes such as becoming longer or taller can be enacted by some factory and tele-operated robots; more complex changes can also be achieved using multiple modules (Alonso-Mora et al, 2012;Revzen et al, 2011), objects (Brodbeck and Iida, 2012), and approaches such as "jamming" (Steltz et al, 2009) or programmable matter/4d printing (An et al, 2014). Outside of robotics, size-changing mechanisms involving (1) elastic/absorbent materials, (2) telescopic cylinders, (3) scissor linkages, (4) folding, and (5) rack and pinions, have been used to build artifacts such as (1) balloons; (2) construction vehicles; (3) furniture, elevators, architectural displays and toys (e.g., Hoberman's combinable Expandagon blocks); (4) maps, satellites (Miura, 1985) and medicinal devices (You and Kuribayashi, 2003); as well as (5) locomotive devices.…”

Developments in 4D-printing: a review on current smart materials, technologies, and applications

“…Understanding these mechanisms is critical for 4D-printing functional structures. The mathematical modeling field includes backward prediction, which provides the printing profile given a target shape and function [57][58][59][60] and forward prediction which models the deformation process given the initial profile [43,47,48,59,60]. Many modeling processes can be understood by the comprehensive system developed by Momeni et al who established three basic laws that most 4D-printed structures will follow [61].…”