The following is translated from the original:
cilia are sensory structures that extend from the surface of certain cells. These hair-like structures are known to contribute to the sensorimotor abilities of various organisms, including humans.
In order to perform their physiological functions, cilia must beat synchronously. Although many past studies have begun to explore cilia synchronization, its biological and mechanical basis are not yet fully understood. Part of the reason is that it is difficult to study cilia in vivo samples and under controlled experimental conditions.
Researchers at the Institute of Physics of China Academy of Sciences recently launched a new platform that can be used to recreate the mechanics of cilia and study their behavior in a controlled environment. Their proposed cilia modeling system, published in a paper in Physical Review Letters, consists of a chain of self-propelling robots called HEXBUG.
“This project emerged after Xia Yiming and Hu Zixian built a series of HEXBUG robots for fun, which were originally used to study the collective motion of autonomous thrusters,” Yang Mingcheng, co-author of the paper, told Phys.org.。
“Surprisingly, they found that two HEXBUG chains anchored to shared bases could beat synchronously. We immediately realized that the anchored HEXBUG chains behaved similar to biological cilia and could be used to study synchronization between cilia caused by mechanical coupling alone (i.e., no hydrodynamic effects).”
The co-author of the paper, Dr. David, is an expert on biomilia and has long been studying the synchronicity of cilia in the biological model organism Chlamydomonas rheinatum. As part of his recent work, he evaluated the potential of robotic systems to experimentally replicate cilia behavior.
“To understand the mechanical basis of the interesting dynamics of the anchored HEXBUG chain, we built a simplified theoretical model based on connected self-driving particles,” Yang said. “Subsequently, Xia Yiming conducted Brownian dynamics simulations under a wide range of system parameters and successfully reproduced the experimental observations.”
The simulations conducted in Xia were used to simulate competition and transitions between different gaits in the system, while also accurately predicting its thermodynamics. This in turn could be used to explore the energy rules that may control the evolution of cilia behavior, especially how different synchronized gaits compete and emerge for energy.
“After some attempts, we realized that current simple systems are evolving towards a steady state with maximum energy dissipation, i.e., maximum entropy production,” Yang said.
The model system created by the research team consists of a series of micro robots (called HEXBUG robots) that are interconnected to form a chain. To connect the robot, the researchers used some hats made through 3D printing. The joints on these covers define the maximum angle that adjacent HEXABUG robots can bend. This angle ultimately controls the waveform of the beating motion of the cilia generated by the system.
After anchoring two chains on the same base (similar to algae cell bodies) and loading different weights on the base, Yang and his colleagues found that stronger friction (greater weight) hindered the chain’s ability to synchronize. In addition, they also changed the power supply of the artificial cilia system to an external DC power supply. This allows them to control the effective driving force of the system, which is related to the applied voltage.
“These experimental systems are well modeled in simulations,” Yang said. “The HEXBUGS is abstracted as a self-propelling rod, their mechanical interaction is captured by a connecting spring, and the friction force of the base and active driving force as the two main control parameters. After systematically characterizing the simulation system and benchmarking it with experimental results, we are confident that the simulation captures the essence of the real setup.”
As part of the research, the team deployed their systems in simulated and experimental environments. The simulation system provides them with huge possibilities to explore the system parameter space to make detailed predictions of gait transitions and basic physics.
“Simulations can calculate energy, which is impossible to calculate accurately through experiments,” Yang explained.
Yang and his colleagues have successfully developed a controlled platform that can be used to study the mechanically-mediated synchronous behavior observed in cilia. In the future, the system they propose could be used by other researchers around the world to further advance the understanding of cilia and their underlying physics, which is often difficult to explore experimentally.
“This platform can be used to realize and study complex cilia behavior in a controlled manner,” Yang said. “This may help biophysicists studying cilia synchronization test their working hypotheses.”
If you want to learn more, you can click on the link below the video.
Thank you for watching this video. If you like it, please subscribe and like it. thank
Original text:https://phys.org/news/2024-08-robotic-platform-complex-ciliary-behavior.html
Oil tubing: