Development of a Five-Fingerd Biomimetic Soft Robotic Hand by 3D Printing the Skin and Skeleton as One Unit

TL;DR

This work presents a skin-skeleton integrated soft robotic hand fabricated by SLA 3D printing, where most of the hand is a single flexible part combined with a few rigid bones. Driven by seven tendons, the five-finger design achieves $15$ degrees of freedom with a simple four-part assembly completed in under an hour. The skin-skeleton interface incorporates dorsal wrinkles and palm-side holes to reduce tendon tension and enable reliable flexion, while tendons run inside the skeleton to minimize epidermal pressure. Experiments demonstrate versatile grasping (16 postures), dial manipulation, and robust impact resistance, highlighting a practical, ship-ready soft hand with potential for low-cost, rapid deployment in automation and human–robot interaction.

Abstract

Robot hands that imitate the shape of the human body have been actively studied, and various materials and mechanisms have been proposed to imitate the human body. Although the use of soft materials is advantageous in that it can imitate the characteristics of the human body's epidermis, it increases the number of parts and makes assembly difficult in order to perform complex movements. In this study, we propose a skin-skeleton integrated robot hand that has 15 degrees of freedom and consists of four parts. The developed robotic hand is mostly composed of a single flexible part produced by a 3D printer, and while it can be easily assembled, it can perform adduction, flexion, and opposition of the thumb, as well as flexion of four fingers.

Figures (12)

• Figure 1: Overview of skin-skeleton integratedrobot hand
• Figure 2: Structure of the human hand and names of its parts
• Figure 3: Overview of skin-skeleton integrated parts
• Figure 4: Finger models used in tension tests
• Figure 5: Resulting graph of tension due to flexion of each finger model.(The blue line is the maximum tension of the proposed method)