Monday, July 22, 2024

Microelectronics give researchers a remote control for biological robots

Researchers at the University of Illinois Urbana-Champaign, Northwestern University, and collaborating institutions have developed hybrid bioelectronic robots equipped with battery-free and micro-inorganic light-emitting diodes for wireless control and real-time communication. The team says their hybrid “eBiobots” are the first to combine soft materials, living muscle, and microelectronics.

“Integrating microelectronics allows the merger of the biological world and the electronics world, both with many advantages of their own, to now produce these electronic biobots and machines that could be useful for many medical, sensing, and environmental applications in the future,” said study co-leader Rashid Bashir.

The team has pioneered the development of biobots, small biological robots powered by mouse muscle tissue grown on a soft 3D-printed polymer skeleton. They demonstrated walking biobots in 2012 and light-activated biobots in 2016. The light activation gave the researchers some control, but practical applications were limited by the question of how to deliver the light pulses to the biobots outside of a lab setting.

Northwestern University professor John A. Rogers came up with a solution. He and his team helped integrate tiny wireless microelectronics and battery-free micro-LEDs – this allowed the researchers to remotely control the eBiobots.

“This unusual combination of technology and biology opens up vast opportunities in creating self-healing, learning, evolving, communicating, and self-organizing engineered systems. We feel that it’s a very fertile ground for future research with specific potential applications in biomedicine and environmental monitoring,” said Rogers, a professor of materials science and engineering.

Researchers eliminate bulky batteries and tethering wires to give the biobots the freedom of movement required for practical applications. The eBiobots use a receiver coil to harvest power and provide a regulated output voltage to power the micro-LEDs.

The researchers can send a wireless signal to the eBiobots that prompts the LEDs to pulse. The LEDs stimulate the light-sensitive engineered muscle to contract, moving the polymer legs so that the machines walk. The micro-LEDs are so targeted that they can activate specific portions of muscles, making the eBiobot turn in the desired direction.

Using computational modeling, the researchers optimize the eBiobot design and component integration for robustness, speed, and maneuverability. The interactive design and additive 3D printing of the scaffolds allowed for rapid cycles of experiments and performance improvement. The design allows for possible future integration of additional microelectronics, such as chemical and biological sensors, or 3D-printed scaffold parts for functions like pushing or transporting things that the biobots encounter, the researchers said.

The integration of electronic sensors or biological neurons would allow the eBiobots to sense and respond to toxins in the environment, biomarkers for disease, and more possibilities, they say.

“In developing a first-ever hybrid bioelectronic robot, we are opening the door for a new paradigm of applications for health care innovation, such as in-situ biopsies and analysis, minimum invasive surgery, or even cancer detection within the human body,” said co-first author Zhengwei Li.

Journal reference:

  1. Yongdeok Kim, Yiyuan Yang, Xiaotian Zhang, Zhengwei Li, Abraham Vázquez-Guardado, Insu Park, Jiaojiao Wang, Andrew I. Efimov, Zhi Dou, Yue Wang, Junehu Park, Haiwen Luan, Xinchen Ni, Yun Seong Kim, Janice Baek, Joshua Jaehyung Park, Zhaoqian Xie, Hangbo Zhao, Mattia Gazzola, John A. Rogers, Rashid Bashir. Remote control of muscle-driven miniature robots with battery-free wireless optoelectronics. Science Robotics, 2023; DOI: 10.1126/scirobotics.add1053