Scientists create self-focusing robotic eye that works without electricity

Scientists at Georgia Institute of Technology have developed a self-focusing robotic “eye” made from hydrogel that operates without electricity or batteries, automatically adjusting its focus in response to light intensity. The breakthrough lens is sensitive enough to distinguish microscopic details like individual hairs on an ant’s leg and could enable autonomous soft robots to operate in environments where traditional electronic sensors would fail.

How it works: The lens combines a hydrogel framework with graphene oxide particles that respond to light by heating up and changing the material’s shape.
• The hydrogel contains polymers that trap and release water, allowing it to shift between liquid-like and solid-like states when heated or cooled.
• Embedded graphene oxide particles absorb light across the visible spectrum and generate heat when exposed to sunlight-intensity illumination.
• As the particles warm up, the hydrogel shrinks and stretches the lens to achieve focus; when light is removed, the material swells and releases tension.

What it can see: The lens demonstrated microscopic imaging capabilities that rival traditional glass lenses in laboratory testing.
• Researchers successfully imaged 4-micrometer gaps between tick claws, 5-micrometer fungus filaments, and 9-micrometer stubble on ant legs.
• The system can function as a replacement for glass lenses in conventional light microscopes while operating entirely without power.
• The hydrogel responds to the full visible light spectrum, making it versatile for different imaging conditions.

The big picture: This development represents a significant advance in soft robotics, where traditional rigid sensors and electronics are impractical for many applications.
• Soft robots are increasingly valuable for wearable technology that integrates with human bodies and autonomous devices operating in hazardous or uneven terrain.
• The mechanical structure mimics human eye configuration, but the adaptable hydrogel could potentially replicate vision systems from other animals like cats or cuttlefish.

What’s next: The research team is integrating the lens into microfluidic valve systems made from the same responsive hydrogel material.
• This integration would create intelligent, autonomous camera systems powered entirely by the light used for imaging.
• Future applications could include mimicking specialized animal vision, such as a cat’s ability to detect camouflaged objects or a cuttlefish’s capacity to see colors beyond human perception.

What they’re saying: “If you’re looking at robots that are softer, they’re squishy, they maybe don’t use electricity, then you have to think about how you’re going to do sensing with these robots,” study first author Corey Zheng, a doctoral student in biomedical engineering at Georgia Institute of Technology, told Live Science.
• “We can actually control the lens in really unique ways,” Zheng added, highlighting the system’s adaptability compared to traditional vision systems.