Light‑Powered Gel Robot That Swims Like a Leech

A new soft robot moves through water using light instead of batteries. The device is made from a single sheet of liquid-crystal gel patterned so its internal molecules twist to produce a traveling wave when illuminated.

How It Works

• Motion: A laser scans across the gel sheet, causing it to bend rhythmically and propel itself forward at about half a millimeter per second.
• Direction Control: By shining light on specific parts of its body, the robot can change direction—upward, left, or right—allowing it to swim freely in three-dimensional space.
• Underwater Mobility: Experiments show a gel “leech” navigating narrow tunnels in salty water, demonstrating untethered movement.

Advanced Capabilities

• Combined Robots: Two gel leeches can be joined into one larger piece. By controlling where the light hits over time, the combined robot can swim straight or spin around itself.
• Object Transport: This dual-mode movement allows it to carry small objects along a user-designed path, opening possibilities for tiny medical devices that deliver drugs or perform inspections inside the body.

Unique Advantages

• No Electronics Needed: All motion comes from the material’s internal structure and external light, keeping the robot lightweight and flexible.
• Precision Motion: The technology shows how precise molecular design can translate simple optical signals into complex, lifelike motion in fluid environments.