Electrical impulses in Biohybrid Robots

Novel Approach in Robotic Development: Fungal Mycelia Integration

Introduction to the Research

Robotic construction takes time, technical know-how, proper materials--and, at times, a dash of fungal support.

Cornell researchers have introduced a novel component in developing new robots, sourcing not from the lab but the forest floor: fungal mycelia. By leveraging mycelia's natural electrical signals, they uncovered a new method for controlling "Biohybrid" robots, potentially enabling more responsive environmental interactions than purely synthetic models.

Publication Details

The research paper, "Sensorimotor Control of Robots Mediated by Electrophysiological Measurements of Fungal Mycelia," has been published in Science Robotics. The study's lead author, Anand Mishra, works in the Organic Robotics Lab, which is directed by Professor Rob Shepherd, the senior author of the paper.

Future Implications

"This paper marks the beginning of a series of studies exploring the fungal kingdom's potential to enhance robots' environmental sensing and autonomy," Shepherd explained. "By integrating mycelium into  the robot's electronics, we enabled the biohybrid machine to detect and react to environmental stimuli. While we used light as the input in this study, future applications may involve chemical signals. For instance, robots could eventually monitor soil chemistry in agriculture and autonomously determine fertilizer application, potentially reducing the downstream impacts such as harmful algal blooms.

Inspiration and challenges in Robotics

Inspiration from Nature

In envisioning the next generation of robots, engineers have drawn significant inspiration from the animal kingdom, creating machines that replicate the movements, environmental sensing, and even thermoregulation of living organisms. Some of these robots integrate living materials like muscle cells, but maintaining the health and functionality of such complex biological systems presents considerable challenges. After all, sustaining a living robot isn't straightforward.

Advantages of Mycelia

Mycelia, the subterranean vegetative structures of mushrooms, possess several advantageous characteristics. They thrive in harsh environments and are capable of detecting and responding to chemical and biological signals from multiple inputs.

Technical Integration and Expertise

System Development

"When considering synthetic systems, such as passive sensors, they are typically designed for a singular function. In contrast, living systems are responsive to a variety of stimuli, including touch, light, heat, and even some unknown signals," Mishra explained. "This adaptability is why we believe that future robots, designed for unpredictable environments, can benefit from integrating these living systems to respond to any unforeseen inputs."

Successfully merging mushrooms with robotic technology involves more than just advanced technical knowledge and botanical proficiency.

"A comprehensive knowledge of mechanical engineering, electronics, mycology, neurobiology, and signal processing is necessary to construct this system," Mishra noted. "These area of expertise must come together."

Collaborating with interdisciplinary specialists, Mishra worked with Bruce Johnson, senior research associate in neurobiology and behavior, to understand the recording of electrical signals in neuron-like ionic channels of mycelia. He also received guidance from kathie Hodge, associate professor of plant pathology, on growing clean mycelial cultures, tackling the issue of contamination when integrating electrodes into fungi.

Mishra's developed system features an electrical interface designed to filter out vibrations and electromagnetic interference, enabling precise real-time recording and processing of the mycelia's electrophysiological activity. It includes a controller inspired by central pattern generatiors, functioning like neural circuits. This system captures raw electrical signals, analyzes rhythmic spikes, and translates them into digital control signals for the robot's actuators.

Experimental Results

Biohybrid Robots and Testing

The team constructed two biohybrid robots: one designed as a soft, spider-like robot and another as a wheeled robot. The robots underwent three experimental phases:

1. Natural Signal Response: Initially, the robots walked and rolled in response to the mycelia's natural signal spikes.
2. Environmental Stimulation: Ultraviolet light stimulation altered their gaits, showcasing mycelia's environmental responsiveness.
3. Signal Overriding: In the final phase, researchers successfully overrode the mycelia's intrinsic signals.

Broader Implications

These findings have far-reaching consequences beyond the domains of robotics and fungal studies.

Mishra explained that this project transcends mere robot control; it's about establishing a genuine interaction with living systems. By interpreting the signals, we gain insights into underlying stresses, which the robot visualizes.

Co-Authors and Contributions

The team of co-authors includes Johnson, Hodge, Jaeseok Kim from the University of Florence, Italy, and undergraduate research assistant Hannah Baghdadi.

Source