Biohybrid machinery: Fungus-driven robots

New Atlas discusses a biohybrid machine that does not combine plant or animal cells with machines. Instead this is the first report of a biohybrid fungus robot:

Fungus learns to drive in "biohybrid" robots

A few decades of human engineering can’t compete with billions of years of evolution, so rather than reinvent the wheel it’s often better to just incorporate nature’s versions of things into synthetic systems. That’s why we have robots with super-sensitive locust ears, robot fish that swim thanks to beating human heart cells, and robots that crawl using sea slug muscles. Ultimately, this method could make for more responsive robots.

Now, scientists at Cornell University have developed a new biohybrid robot that uses components from beyond the animal kingdom: fungi. These organisms sense and communicate using electrical signals sent through their mycelium, the root system. So the team grew the mycelium directly into the electronics of a robot, tapping into those natural signals to drive the machine.

The researchers created an electrical interface that accurately records the electrophysiological activity from the mycelia, processes it, and converts it into a digital signal that the robot can understand. When sent to the actuators, the robot moves in response to the fungus, which itself sends out signals in response to environmental changes, like light.

The team built two versions of these biohybrid robots. One is a relatively simple-looking wheeled unit, while the other is kind of spider-shaped with soft legs. In both cases, a Petri dish of fungus sits on top, where it can respond to light and other stimuli, before sending signals to the legs or wheels to get moving.

In one experiment, scientists shone ultraviolet light onto the fungus, which induced the fungus to change the way the robot moved. Light is the only direct stimulus tested so far, but researchers plan to incorporate multiple simultaneous inputs, such as chemical stimulants, e.g., the scent of food, and changes in heat and pressure along with light. Fully man-made machines require specialized sensors for each kind of stimulus or input. But living systems can usually respond to multiple inputs without a need for man-made sensors for each stimulant.

Researchers are interested in fungus biohybrids because some fungi are much tougher than plant or animal cells. Some fungi can survive under harsh conditions that would kill plant or animal cells. 

A computer translates fungal electrical signals into commands to move the robot. One question is whether or how much can a fungus robot learn. One can imagine that is also a planned experiment. Some existing research indicates that fungi arguably have at least some limited ability to learn and remember. One article commented that as fungi grow, they constantly sense their environment, learning, and making decisions about how to respond.

A summary of the research paper, Sensorimotor control of robots mediated by electrophysiological measurements of fungal mycelia:

Many biohybrid robots are powered by animal or plant cells, which are sensitive to specific culture procedures and limited to short life spans. In contrast, fungi can be easily cultured and are robust in extreme conditions. Taking advantage of fungal mycelia’s natural light sensitivity, Mishra et al. developed an electrical interface to both house the mycelia and measure their electrophysiological action potentials. A control model was then developed to use the rhythmic voltage spikes from the living mycelia to control the locomotion of both a soft starfish-inspired robot and a wheeled robot. Robot trajectories could be altered by stimulating the mycelia with ultraviolet light.

Fungi are part of Earth's internet -- they are chatty and talk to plants all the time:

By Germaine