Climbing plants, such as vines, use structures called tendrils to further their journey upward. Tendrils stretch out and coil around nearby suitable support structures, and now researchers have been able to mimic this behavior with soft robotics.
Hailing from the Center for Micro-BioRobotics at Italy’s Istituto Italiano di Tecnologia (IIT), the team first observed their real-life muse. By using a hydraulic principle called osmosis, tendrils exploit water transport in their cells, tissues, and organs in order to move. So, the researchers designed their tendril-robot to climb “using the same physical principles determining water transport in plants,” according to IIT.
The team used a mathematical model to determine the hydraulic-driven robot’s optimal size. If it was built too large, its movements’ speed would suffer. Then, the robot was molded to mimic the shape of a tendril, so it could perform reversible movements.
In the end, the team had a robo-tendril made of a flexible PET tube that contained a liquid with electrically charged particles (ions), and a 1.3 V battery that attracted and immobilized the ions.
After further developments, the robot may help design wearable devices that can alter their shape, and flexible robotic arms.
The research team was led by Barbara Mazzolai, who, according to IIT, “was listed in 2015 among the 25 most influential women in robotics by RoboHub, and in 2012 she coordinated the EU-funded project ‘Plantoid’ that brought to the first plant robot worldwide.”
Next, Mazzolai and her colleagues will coordinate the “GrowBot” project, which aspires to create a robot that can “manage its growth and adaptation to the surrounding environment with the capability to recognize the surfaces to which it attaches, or the supports to which it anchors. Just like the real climbing plants do.”
To learn more, read the article, “A variable-stiffness tendril-like soft robot based on reversible osmotic actuation,” published in Nature Communications.
Below you can see the tendril-like soft robot in action.
