Soft Hands represent a departure from classical robot hand design, which often relies on exact models and precise planning of contact points. Instead, we aim to increase robustness and safety through the use of soft materials and flexible mechanics. This softness allows us to exploit contact with the environment and use it in robust grasping and manipulation strategies.
We developed the RBO Hand 3 to understand the necessary soft-robotic aspects, and formulate the concept of morphological-computation.
Steffen Puhlmann, Adrian Sieler
The RBO Hand 3 is a highly dexterous and versatile soft hand based on pneumatic actuation. It advances on its predecessor by combining 16 actuated degrees of freedom with intrinsic mechanical compliance in an anthropomorphic design. Special attention was paid to the design of the opposable thumb. The RBO Hand 3 is inherently safe and highly robust for externsive real-world experimentation. It closely replicates the functioning of its human counterpart to facilitate transfer of insights to human dexterity, and it is capable of dexterous grasping and manipulation
The RBO Hand 2 is a hand made from PneuFlex actuators mounted on a flexible, printed scaffold. The hand was developed to investigate the capabilities and limits of hands when relying only on soft, deformable structures. The unique deformability provides several advantageous benefits to robots trying to interact with the environment:
The result of our research are several hand prototypes, which we refer to collectively as Soft Hands. RBO Hand 2 is the latest model and used in our lab for research into grasping strategies.
If you want to build your own, you are welcome to do so! We have published the CAD models for the PneuFlex actuators
The RBO Hand (published in 2013) was the first soft hand that employed PneuFlex actuators. It uses 3 pairs of parallel and straight PneuFlex actuators. The finger are also partially connected to each other. The hand has a passively bendable rubber sheet acting as a palm in opposition to the fingers.
For the control of the pneumatic RBO Hand 2 we had to create our own hardware. We developed the "PneumaticBox", which consists of valve array, a single-board computer, and a custom printed circuit board.
A detailed description of the hard- and software can be found in the Tutorial section.
We develop a set of production processes and a complete design toolchain for soft continuum actuators under the name PneuFlex. The toolchain consists of several components:
The term Morphological Computation emphasizes the notion, that the way a robot is built (its morphology) provides a substantial contribution to the computation of reactive behavior. Intuitively, controlling a robot on the higher level gets simpler when the robot's body provides more Morphological Computation to the task.
At RBO Lab, we investigate methods to quantify the contribution of a robot's morphology to a specific task, and ways of increasing that share. We use soft hand design as a use case that provides sufficient complexity and cooperate with MPI Leipzig on the supporting theory.
Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - EXC 2002/1 "Science of Intelligence" - project number 390523135
German Priority Program DFG-SPP 2100 “Soft Material Robotic Systems” - project number 405033880.