Literature Survey and Technologies Used

The project is based on the Fin Ray Effect. This is a natural phenomenon where internal ribs cause a structure to wrap around an object, much like a fish's fin. The gripper was designed using Fusion 360 and was later tested for deformation using Ansys. The grippers were then manufactured using 3d printing. Finally, Arduino IDE was used for controlling the NEMA Stepper motor, that drove the entire mechanism.

Methodology

The design features a triangular shape with diagonal ribs inside to keep it both flexible and strong. TPU (Thermoplastic Polyurethane) was selected as the material because it is stretchy, durable, and easy to 3D print. During the simulation phase, the team tested the design using a digital mesh. They discovered that the internal supports at 5 degrees angle allowed the gripper to curve and adapt to objects better than a design with no angle. To move the gripper, a NEMA 17 stepper motor pushes a central link, which moves a wooden four bar mechanism to open and close the fingers.

Results

The design with the 5 degree angle worked best, reaching a maximum bend of 12.83 mm when 10N force was applied. The final build successfully combined the 3D printed TPU fingers with a sturdy T slot aluminum frame and laser cut wooden connecting rods. During testing, the gripper was able to wrap itself around various shapes and pick up delicate items without breaking them.

Conclusions and Future Scope

Fins with angled internal supports are more flexible and easier to use than standard designs. In the future, the project could focus on making the motor system smaller or changing the frame shape to help the gripper perform more specialized tasks.
 

References

1. Crooks, W. et al. (2016). Fin Ray Effect Inspired Soft Robotic Gripper. Frontiers in Robotics and AI, 3, 70. https://doi.org/10.3389/frobt.2016.00070
2. https://www.frontiersin.org/journals/robotics-and-ai/articles/10.3389/frobt.2016.00070/full#F4
3. https://source-robotics.com/blogs/blog/soft-robotic-grippers-fin-ray-effect?srsltid=AfmBOoptqd3Wn6aHSNmXDG-xanfHJDChlhJXRsSNUEP9Cotb0R5HdEYP
4. https://howtomechatronics.com/tutorials/arduino/how-to-control-stepper-motor-with-a4988-driver-and-arduino