3D printing soft gripper stiffened by passive particle jamming


A variety different kinds of soft actuators based on different working principles have been developed. Most soft grippers do not allow stiffness modulation when grasping, these actuators cannot provide very high stiffness and large grasp force, thus the weight that such a soft gripper can hold is limited.

Researchers have proposed some ways to increase the stiffness of a soft gripper. For stiffness modulation of soft grippers, current methods need dedicated design and control, complicating both the actuator geometric configuration and the control process. Fabrication of multi-functional soft grippers is time-consuming and its processes are complex.

The proposed 3D printing soft robotic gripper is stiffened by passive particle jamming, shown as in Fig. 1. We aim to design a soft gripper that can achieve higher stiffness as well as simplify the design process. The objectives and significance of the proposed gripper are:

  • To stiffen a pneumatic soft actuator in object grasping without the need of any control process.
  • To increase the stiffness variation band so that both soft and hard objects could be grasped.
  • To 3D print the soft actuator without the need of additional assembly processes.

This research is a revision and upgrade according to a published paper:  Li, Y. T., Chen, Y. H., Yang, Y., & Wei, Y. (2017). Passive Particle Jamming and Its Stiffening of Soft Robotic Grippers. IEEE Transactions on Robotics.

3D printing soft finger stiffened by passive particle jamming.
Fig. 1. 3D printing soft finger stiffened by passive particle jamming. (a) Normal 3D printed soft actuator. (b) Soft actuator filled with particles in loose state. (c) Particles in the soft finger are passive jammed