Artificial tribotactic microscopic walkers: walking based on friction gradients

Area of Science:

• Physics
• Robotics
• Biophysics

Background:

• Friction is crucial for locomotion, but its role in inhomogeneous environments is understudied.
• Existing locomotion models primarily focus on homogeneous settings.

Purpose of the Study:

• Introduce and demonstrate tribotaxis: locomotion guided by friction gradients.
• Investigate microwalker migration in response to varying friction coefficients.

Main Methods:

• Experimental setup with microwalkers interacting with a substrate.
• Stochastic actuation of microwalkers.
• Simulations and biased random walk theory.

Main Results:

• Microwalkers successfully migrated to regions of higher friction.
• Experimental results align with theoretical models and simulations.
• Demonstrated a direct correlation between receptor density and effective friction.

Conclusions:

• Tribotaxis is a viable locomotion mechanism in inhomogeneous environments.
• This principle has potential applications in artificial and natural locomotion.
• Friction gradients can effectively guide movement, analogous to chemotaxis.