MagicTac: A Novel High-Resolution 3D Multi-layer Grid-Based Tactile Sensor

TL;DR

MagicTac addresses the trade-off between high-resolution tactile sensing and affordability by introducing a 3D multi-layer grid-based skin produced through integral printing. The design integrates a perception module with a transparent, grid-embedded contact skin, enabling rich deformation sensing without silicone casting or manual marker assembly. Key findings include a low manufacturing cost of £4.76 and a per-unit production time of about 24.6 minutes, plus demonstrations of tactile reconstruction, 100% grating-identification accuracy, and sub-millimeter 3D contact localization. This work suggests MagicTac as a scalable, cost-effective platform for tactile sensing to support dexterous robotic manipulation.

Abstract

Accurate robotic control over interactions with the environment is fundamentally grounded in understanding tactile contacts. In this paper, we introduce MagicTac, a novel high-resolution grid-based tactile sensor. This sensor employs a 3D multi-layer grid-based design, inspired by the Magic Cube structure. This structure can help increase the spatial resolution of MagicTac to perceive external interaction contacts. Moreover, the sensor is produced using the multi-material additive manufacturing technique, which simplifies the manufacturing process while ensuring repeatability of production. Compared to traditional vision-based tactile sensors, it offers the advantages of i) high spatial resolution, ii) significant affordability, and iii) fabrication-friendly construction that requires minimal assembly skills. We evaluated the proposed MagicTac in the tactile reconstruction task using the deformation field and optical flow. Results indicated that MagicTac could capture fine textures and is sensitive to dynamic contact information. Through the grid-based multi-material additive manufacturing technique, the affordability and productivity of MagicTac can be enhanced with a minimum manufacturing cost of 4.76 GBP and a minimum manufacturing time of 24.6 minutes.

Figures (8)

• Figure 1: Overview of MagicTac: this design inspired by the magic cube, features a 3D multi-layer, grid-based tactile sensor. The 3D grid-based structure is visible through the mesh-like texture of the skin surface.
• Figure 2: A: MagicTac assembly diagram, an exploded view of the subassemblies. B: Tactile sensing schematic, with a section view of MagicTac.
• Figure 3: A: The schematic of 3D multi-layer grid-based structure, shown in top and side view. B-E: These examples illustrate the deformation in multiple contact situations, including stationary, translation, rotation, and press. The ability of this structure to map tactile features derives from the relative motion between the different layered grid cells, and their inherent elasticity. This characteristic forms the basis for the analogy to the Magic Cube.
• Figure 4: Comparison of VBTS fabrication processes using different manufacturing methods. A: Mould-formed method has the highest time cost and process complexity; B: Split-printing way eliminates the cost of mould making, but lens assembly and internal gel injection still make the overall process cumbersome; C: Integral-printing method requires tiny pre-processing and post-processing work, thereby reducing time and labor costs significantly.
• Figure 5: A: The printing size of single MagicTac. B: Printing batch of MagicTacs on the print tray. C: The trends of average printing time and price related to batch production.