4D printing : towards biomimetic additive manufacturing

Abstract

Inherent across all scales in Nature's material systems are multiple design dimensions, the existences of which are products of both evolution and environment. In human manufacturing where design must be preconceived and deliberate, static artifacts with no variation of function across directions, distances or time fail to capture many of these dimensions. Inspired by Nature's ability to generate complex structures and responses to external constraints through adaptation, "4D printing" addresses additive fabrication of artifacts with one or more additional design dimension, such as material variation over distance or direction and response or adaptation over time. This work presents and evaluates a series of enabling explorations into the material, time and information dimensions of additive manufacturing: a variable elasticity rapid prototyping platform and an approach towards Digital Anisotropy, a variable impedance prosthetic socket (VTS) as a case study of interfaces between nature and manufacture, CNSilk as an example of on-demand material generation in freeform tensile fabrication, and Material DNA as an exploration into embedded spatio-temporal content variation.