Self-assembled structures and machines can be made using origami-inspired manufacturing methods. In particular, self-folding of two-dimensional materials using shape memory polymers and embedded electrical circuits has been utilized to build robots and structures in an inexpensive and rapid manner. In order to build increasingly complex and functional self-folding machines, however, methods for interaction with the environment are necessary. This paper presents and characterizes three types of self-folding sensors: a mechanical switch, a capacitive contact sensor, and a velocity sensor. We utilize specialized fold patterns to create cyclic mechanical linkages as well as additional composite layers such as magnetic sheets to build these sensors. We demonstrate the integration of two of these sensors, the switch and the contact sensor, into a lamp that can self-fold and immediately begin responding to its surroundings.

Nature regularly uses self-folding as an efficient approach to automated fabrication. In engineered systems, however, the use of self-folding has been primarily restricted to the assembly of small structures using exotic materials and/or complex infrastructures. In this paper we present three approaches to the self-folding of structures using low-cost, rapid-prototyped shape memory laminates. These structures require minimal deployment infrastructure, and are activated by light, heat, or electricity. We compare the fabrication of a fundamental structure (a cube) using each approach, and test ways to control fold angles in each case. Finally, for each self-folding approach we present a unique structure that the approach is particularly suited to fold, and discuss the advantages and disadvantages of each approach.