“The field of soft robotics (robots made from intrinsically soft materials such as silicons and rubbers) has been growing rapidly in recent years. Soft robots can be advantageous in comparison to their hard counterparts because they are flexible, adaptable to new environments, and they foster safer human-robot interaction. Soft robotic grippers, in particular, can be useful for handling delicate objects without causing damage.
This Instructable serves as a detailed guide on how to construct soft robotic “fingers” that can be easily operated with a simple hand pump. The STL files for the 3 piece mold can be found at the bottom of the page, in addition to the STL file for a central hub which will allow you to create a fully functioning 4-fingered soft robotic gripper. This project is ideal for soft robot enthusiasts and classrooms alike, with relatively few supplies needed and fast fabrication times.
The soft robot in this Instructable was inspired by the Whiteside’s research group at Harvard and their work with creating pneumatic networks: https://gmwgroup.harvard.edu/soft-robotics. Inspiration was also drawn from the extensive resources at Soft Robotic Toolkit.
3D printer (I used a LulzBot Taz 5, but any printer should work)
PLA filament (ABS or any other filament type should work as well, just make sure it is compatible with Ecoflex 00-50)
Trial size kit of Ecoflex 00-50. You can also use Ecoflex 00-30, but the 00-50 is more durable and preferred if possible
Popsicle stick or coffee stirrer
Container with volume marks to measure Ecoflex. Can also use a scale if you have access. You just need some way to measure parts A and B of the Ecoflex into a 1:1 ratio by mass or by volume.
Cotton fabric (about 1 square foot will make several robots)
Optional extra materials (needed for full 4-fingered claw)
Plastic tubing (1/8 inch Outer Diameter) - about 2 feet will be plenty”