Cross-Sectional 4D-Printing: Upscaling Self-Shaping Structures with Differentiated Material Properties Inspired by the Large-Flowered Butterwort (Pinguicula grandiflora)

Abstract

Extrusion-based 4D-printing, which is an emerging field within additive manufacturing, has enabled the technical transfer of bioinspired self-shaping mechanisms by emulating the functional morphology of motile plant structures (e.g., leaves, petals, capsules). However, restricted by the layer-by-layer extrusion process, much of the resulting works are simplified abstractions of the pinecone scale’s bilayer structure. This paper presents a new method of 4D-printing by rotating the printed axis of the bilayers, which enables the design and fabrication of self-shaping monomaterial systems in cross sections. This research introduces a computational workflow for programming, simulating, and 4D-printing differentiated cross sections with multilayered mechanical properties. Taking inspiration from the large-flowered butterwort (Pinguicula grandiflora), which shows the formation of depressions on its trap leaves upon contact with prey, we investigate the depression formation of bioinspired 4D-printed test structures by varying each depth layer. Cross-sectional 4D-printing expands the design space of bioinspired bilayer mechanisms beyond the XY plane, allows more control in tuning their self-shaping properties, and paves the way toward large-scale 4D-printed structures with high-resolution programmability.

Stereo Camera Setup for 360° Digital Image Correlation to Reveal Smart Structures of Hakea Fruits

“…One way to complete the transfer from the natural principle to a technical solution is the subsequent 4D-printing of prototypes. In this context, more and more work is currently being completed with the aim of developing self-shaping components or materials [ 70 , 71 ].…”

Investigation of the resilience of cyclically actuated pine cone scales of Pinus jeffreyi

“…4D printed hygromorphs are a developing area of additive manufacturing used in architectural design. The inspiration for these structures often arises from the hygroscopic movements of plants, such as the large-flowered butterwort (Pinguicula grandiflora [8]), silver thistle (Carlina acaulis ssp. caulescens [9]) and pine cones [10].…”

Analysis and Simulation of the Compressive Strength of Bioinspired Lightweight Structures Manufactured by a Stereolithography 3D Printer

“…Hamzehei et al [34] present new 3D metamaterials with zero Poisson's ratio for energy absorption applications using SLA 3D printing. Sahin et al [35] use a new 4D-printing method by rotating the printed axis of bilayers inspired by the large-flowered butterwort (Pinguicula grandiflora). However, when using this type of 3D printing, the associated manufacturing costs are often not considered despite their importance as another variable to consider.…”