What do you get when you stretch mouse muscle tissue over a polymer skeleton and attach electronics capable of converting radio-frequency energy into light?

Perhaps a bit of shock when the bioelectronic bot begins to move on its own, with no attached power source.

No fewer than 21 boffins affiliated with America's University of Illinois, Northwestern University, and University of Southern California, plus the University of Technology in Dalian, China, describe this feat in an article published on Thursday in the journal Science Robotics.

The authors include: 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, and Rashid Bashir.

Their paper, titled Remote control of muscle-driven miniature robots with battery-free wireless optoelectronics, describes the process of integrating light-sensitive biological tissue, supported by a 3D printed hydrogel scaffold, with a wireless optogenetic sensor.

Optogenetics involves cells that are, or have been made, sensitive to light. In this instance, the researchers have sensitized mouse muscle to light so that the tissue will contract when illuminated.

Activating a light source like a micro-LED typically requires a wired power source like a battery. The makers of this muscular mini robot have chosen instead to transmit power wirelessly through radio-frequency emissions that can be harvested via resonant magnetic induction using an antenna coil.

The gathered energy activates onboard micro-LEDs which motivate muscle contractions that make the whole assembly move, as can be seen in this video demonstration:

These resulting "eBiobots" are less formidable than one might expect when imagining a bioelectronic hybrid - a cyborg. They're more sinew-and-silicon in aspic than Terminator.

And they're slow, moving only about 0.3-0.8 millimeters per second, depending on the number of LEDs are used. Below is a video illustrating the tech:

"Centimeter-scale walking robots were computationally designed and optimized to host on-board optoelectronics with independent stimulation of multiple optogenetic skeletal muscles, achieving remote command of walking, turning, plowing, and transport functions both at individual and collective levels," the paper explains.

"This work paves the way toward a class of biohybrid machines able to combine biological actuation and sensing with on-board computing."

According to the News Bureau of the University of Illinois at Urbana-Champaign, Northwestern University professor John A. Rogers, one of the paper's co-authors, said the project "​​opens up vast opportunities in creating self-healing, learning, evolving, communicating and self-organizing engineered systems."

Rest assured the researchers are looking at medical and environmental sensing applications for this technology. ®

https://www.theregister.com//2023/01/21/mouse_muscle_cyborg_light/