SoftAR: Visually Manipulating Haptic Softness Perception in Spatial Augmented Reality

Figure 1: Our proposed concept could allow the user to design the desire to perceived softness and roughness as an input for 3D printing. The system then determines the 3D printing parameters such as infills and surface textures according to the target perceived softness. Then, generate the printing parameters to print with an FDM 3D printer.
Figure 2: A sample 3D printed object with pins and concentric infill structure is used in the experiments 1 and 2. We prepared (a) cubic (CU), (b) line (LI), (c) octet (OC), (d) concentric (CO), (e) grid (GR), (f) cross (CR), (g) triangle (TR), (h) tri-hexagon (TH), and (i) zigzag (ZI) infill structures as the stimuli to explore the perceived softness. The samples show cut 3D printed object to display the internal structure on sides (i.e., user touch the object from the top as shown in white line). In the experiments, the internal structure was not visible to the participants.

Abstract

FDM 3D printers allow massive creativity in personal products, but their potential has been limited due to inability to manipulating material properties. Previous work had demonstrated that the desired roughness could be presented simply by controlling the spatial density of tiny pins on a printed surface. This article offers a means of providing the desired softness perception of a printed surface and the desired roughness to expand the haptic dimension over which a user can exert control. Specifically, we control the softness by manipulating the infill structures of a printed surface. However, it is known that a skin contact area affects softness perception. The roughness, which is controlled by pins’ density, may also affect the perceived softness of a printed surface. Therefore, we investigate how the internal structures and the density of the pins affect softness perception. Through psychophysical experiments, we derive a computational model that estimates the perceived softness from the density of the pins and the infill density of a printed surface.

Motoki Miyoshi, Parinya Punpongsanon, Daisuke Iwai, and Kosuke Sato. SoftPrint: Investigating Haptic Softness Perception of 3D Printed Soft Object in FDM 3D Printers. Journal of Imaging Science and Technology (Proceedings of Printing for Fabrication), Vol. 65, No. 4, pp. 40406:1-40406:8(8). July 2021.

Motoki Miyoshi, Parinya Punpongsanon, Daisuke Iwai, and Kosuke Sato. Investigation of Soft Display using Digital Fabrication and Phase-change Material. In Proceedings of 2021 IEEE 3rd Global Conference on Life Sciences and Technologies (LifeTech), pp. 513-514. Nara, Japan, March 2021.