Micrometer-sized molecular robot changes its shape in response to signal molecules

Area of Science:

• Bioinspired Robotics
• Nanoscale Bioengineering
• Molecular Systems

Background:

• Nanoscale bioengineering advances enable biomolecular devices for sensing, actuation, and logic operations.
• A key goal in bioinspired robotics is assembling micrometer-sized robots from these biomolecular components.

Purpose of the Study:

• To construct an amoeba-like molecular robot exhibiting continuous shape change in response to specific signal molecules.
• To integrate a functional system comprising a body, actuator, and a signal-responsive DNA-based clutch.

Main Methods:

• Constructed a robot with a lipid bilayer vesicle body, a kinesin-microtubule actuator, and a DNA-designed clutch.
• Utilized sequence-designed DNA with chemical modifications as signal molecules to control the DNA clutch.
• Employed light-triggered release of signal molecules to initiate and terminate robot shape change.

Main Results:

• The molecular robot demonstrated continuous shape change when the DNA clutch was engaged by signal molecules.
• Shape-changing behavior was successfully terminated upon light-induced disengagement of the clutch.
• Initiation of shape change by signal input and termination were both successfully demonstrated, confirming system functionality.

Conclusions:

• The study successfully integrated diverse components into a functional molecular robot with controllable motility.
• This work provides a foundational platform for developing more complex and functional molecular systems.
• Demonstrated precise control over robot shape change through a DNA-based signaling mechanism.