# Octopus Robo-Grip (DD-601)

> In February 2020, researchers from Beihang University, Harvard's Wyss Institute and Harvard SEAS, and the automation company Festo published a study in Soft Robotics on octopus arm-inspired tapered soft actuators with suckers. Zhexin Xie and August Domel were co-first authors, and Katia Bertoldi and Li Wen were co-senior authors. The team measured how much octopus arms taper and found that a cone-shaped silicone actuator bends into a wider range of curvatures than a cylindrical one. A steeper taper curls less tightly but pushes with more force. The researchers added suction cups modeled on those of the common octopus (Octopus vulgaris), shrinking from base to tip, and all linked to a single vacuum line. The arm runs on two valves: one pressurizes it to bend, and one applies vacuum to the suckers. Harvard's press release says it gripped thin plastic sheets, mugs, test tubes, eggs, smartphones, exercise balls and even live crabs, and could reach into narrow openings. Xie is also co-inventor of the Festo Tentacle Gripper, a commercial prototype of the idea. In 2023, a Beihang-led team with Li Wen and Cecilia Laschi reported a sensorized soft octopus arm (E-SOAM) in Science Robotics that bends and elongates to reach and grasp. The footage shows a robot arm whose multi-tentacle gripper curls around a ball, a box, a hat and a plant, a demonstration of the same tapered, suction-cup design.

- Department: Tech (also Science)
- First published: 2025-06-20
- Last updated: 2025-06-20
- Permalink: https://detailenjoyer.com/case/octopus-robo-grip/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-601-F01**: A tapered soft arm bends more flexibly than a cylindrical one. _(Write-up · Exhibit A (Taper matters))_
- **DD-601-F02**: The 2020 octopus gripper runs on just two valves. _(Write-up · Exhibit B (Two valves))_

## Write-up

Grabbing like an octopus arm. A tapered soft gripper with suction cups, from Harvard and Beihang.

1. **Taper matters**: Cone-shaped actuators bend into a wider range of curvatures than cylindrical ones.
2. **Two valves**: One valve pressurizes the arm to bend; the other applies vacuum to the suckers.
3. **Modeled suckers**: The suction cups mimic those of the common octopus and shrink toward the tip.
4. **Wide range of objects**: It gripped eggs, mugs, test tubes, phones, exercise balls and live crabs.
5. **Next step**: A 2023 Beihang-led octopus arm (E-SOAM) bends and elongates and carries sensors.

## Related case files

- [RoboWeaving (DD-716)](https://detailenjoyer.com/case/roboweaving/): Another soft-robotics case
- [Gyotaku (DD-671)](https://detailenjoyer.com/case/gyotaku/): Another case featuring octopus arms

## Reel vs. record

- **Note**: 'Uses a muscular hydrostat structure': octopus arms are muscular hydrostats, but the 2020 robot arm is a pneumatic silicone actuator. It mimics the arm's taper and suckers, not its muscle structure.
- **Note**: 'Bend, elongate, and grip': the 2020 gripper bends and grips. Elongation came in a later Beihang-led arm, E-SOAM (Science Robotics, 2023).
- **Note**: 'Developed by Harvard and Beihang University researchers': yes, together with Festo, whose engineer Elias Knubben co-authored the 2020 study.
- **Note**: 'Vacuum-powered suction cups': yes. All the suckers share one vacuum line, controlled by its own valve.
- **Missing**: a steeper taper curls less tightly but pushes with more force, so designers can tune the taper angle for a task.

## Video: Octopus Robo-Grip: Grabbing Like an Octopus Arm

- Duration: 19.0 s · Published: 2025-06-20
- File: https://detailenjoyer.com/assets/videos/DLIgdDVS5h0.mp4

### Transcript

DID YOU KNOW? Animal-inspired robotics harness nature's designs, like the octopus-inspired robotic arm developed by Harvard and Beihang University researchers, mimicking the octopus' flexible tapered tentacles. This soft robotic arm uses a muscular hydrostat structure to bend, elongate, and grip. Equipped with vacuum-powered suction cups, it grasps diverse objects. NOW YOU KNOW!

## Questions & answers

**Q: Which university partnered with Harvard on the 2020 octopus gripper?**  
A: With Festo as well. _(Source: Write-up · Exhibit D (Wide range of objects) · Wyss Institute (Feb 27, 2020): The Tentacle Bot; Harvard SEAS: The Tentacle Bot)_

**Q: What shape gave the arm more flexibility?**  
A: Tapered actuators bend into more curvatures. _(Source: Write-up · Exhibit A (Taper matters) · Xie, Domel et al. (2020): Octopus arm-inspired tapered soft actuators with suckers for improved grasping, Soft Robotics)_

**Q: How many valves control the 2020 gripper?**  
A: One for pressure, one for vacuum. _(Source: Write-up · Exhibit B (Two valves) · Wyss Institute (Feb 27, 2020): The Tentacle Bot; Harvard SEAS: The Tentacle Bot)_

**Q: Which octopus's suckers were the model?**  
A: Octopus vulgaris. _(Source: Write-up · Exhibit C (Modeled suckers) · Xie, Domel et al. (2020): Octopus arm-inspired tapered soft actuators with suckers for improved grasping, Soft Robotics)_

**Q: Which live animal did the gripper pick up?**  
A: Along with eggs and mugs. _(Source: Write-up · Exhibit D (Wide range of objects) · Wyss Institute (Feb 27, 2020): The Tentacle Bot; Harvard SEAS: The Tentacle Bot)_

## Sources

- [Wyss Institute (Feb 27, 2020): The Tentacle Bot](https://wyss.harvard.edu/news/the-tentacle-bot/)
- [Harvard SEAS: The Tentacle Bot](https://seas.harvard.edu/news/tentacle-bot)
- [Xie, Domel et al. (2020): Octopus arm-inspired tapered soft actuators with suckers for improved grasping, Soft Robotics](https://doi.org/10.1089/soro.2019.0082)
- [Xie et al. (2023): Octopus-inspired sensorized soft arm for environmental interaction, Science Robotics](https://www.science.org/doi/10.1126/scirobotics.adh7852)

## Cite this case file

Easterling, Marcus. "Octopus Robo-Grip." The Detail Department (DetailEnjoyer), case file DD-601, last updated Jun 20, 2025. https://detailenjoyer.com/case/octopus-robo-grip/