Robots are gaining new capabilities thanks to plants and fungi

In the TV series Doctor Who, treeborgs supply fresh air to spaceship passengers. Part tree, part robot, these devices convert starlight into oxygen. In Nnedi Okorafor’s fantasy novel Zahrah the Windseeker, children receive their own “flora computers” made of leaves and vines, grown from CPU seeds and shaped into useful tech. Although these devices are fictional, flower-powered machines are getting real as a new generation of biohybrid technology blooms.

Engineers have long strived to make lifelike robots. But re-creating the complex functions of, say, a hand or leaf is impossible with synthetic materials, says Anand Mishra, an engineer at Cornell University. “There is a point where technology limits us.”

Using life-forms to build ma­chines can overcome some of these limits. Living tissue, for example, has evolved all sorts of ways to scope out the environment — seeing light, feeling warmth, smelling and tasting food. To make robots that are similarly sensitive to their sur­roundings, Mishra has turned to fungal tissue.

Fungi aren’t plants, but Mishra is interested in one of fungi’s most plantlike features, mycelia. These rootlike structures tunnel through soil for nutrients and can detect en­vironmental cues such as light, heat and chemicals.

Mishra’s team grew mycelia di­rectly into electrodes attached to two robots. The fungi communicat­ed with the robots through electrical signals called action potentials. These zaps are similar to those produced by heart and nerve cells.

Mycelia produce spontaneous action potentials, which triggered the biobots to walk and roll around. When flashed with ultraviolet light, the mycelia produced stronger zaps, which changed the robots’ gait and showed that the bots could respond to the environment, Mishra’s team reported in 2024 in Science Robotics.

Using fungi in biohybrid robots is still “pretty new,” Mishra says. His team now hopes to test how such tech responds to other cues, such as gases. One way their robots’ sen­sory superpowers might help in the real world is in agriculture. Future “shroom” bots could walk through crop fields, testing soil health and other conditions as they go.

While fungi may help robots bet­ter interact with the world, plant powers could help devices better survive it. “Many artificial [tech­nologies] have a shelf life,” says materials scientist Fabian Meder of the Sant’Anna School of Advanced Studies in Pisa, Italy. Electronics start to break down in a few years. Yet the oldest trees can stand tall for thousands of years. And while broken electronics require repairs, plants can recover from damage and adapt to new environments.

Meder has designed artificial leaves that tap an unlikely energy source: static electricity created by wind.

He places artificial leaves on plants. The fake leaves include a layer of rubber — a material good at building up static charge. When wind rustles one of these bionic plants, the artificial leaves bump into real leaves. This creates stat­ic charges that pass into the inner tissue of the real leaf, producing a current. This energy can be har­vested through electrodes placed in the leaf. Meder’s studies have shown that such devices can light up LEDs.

Working with living materials poses design challenges, such as keeping the living parts alive. Like fungi, plants need certain resources to stay healthy. “Photosynthesis is a big part of that,” Meder says. So engineers might need to use trans­parent materials to make parts that would otherwise block out sunlight.

Meder is excited about this new way to tap a potential energy source: “It’s always about harvest­ing [these] crumbs of energy which we otherwise would just lose.”

Almost like those Doctor Who treeborgs surviving on the light of faraway stars.