Robot Moth Grows a UV Sensor From 3 ml of Artificial Blood

A moth-shaped soft robot can grow a brand-new ultraviolet sensor out of chemicals circulating in its own artificial blood, researchers at the University of Tartu and the Italian Institute of Technology reported. When ultraviolet light hits a chosen patch of the 3D-printed body, pyrrole in the fluid polymerizes into conductive polypyrrole, and the patch begins reporting light as a change in electrical resistance.

New Atlas detailed the Advanced Science study on Nov. 5, 2026, quoting first author Kadri-Ann Pankratov, a University of Tartu Ph.D. student. The prototype cannot fly and does not choose its own sensor sites, but it shows a circulating fluid doing more than cooling or hydraulics: it delivers the feedstock for on-demand sensing.

How the robot moth grows a sensor

The body is printed from translucent plastic laced with tiny veins. A small pump pushes about 3 milliliters (0.1 fluid ounces) of liquid through those channels. Some of the fluid seeps roughly a hundredth of a millimeter into the surrounding plastic. That liquid carries pyrrole plus a light-activated additive. With a stencil guiding the UV exposure, a selected wing patch turns black as polypyrrole forms.

Gold wires embedded during printing pick up the electrical change, so the robot grows the sensing material rather than the wiring. Afterward, UV flashes briefly drop the patch’s resistance; an onboard chip answers by blinking an LED or flapping the wings. The wings themselves bend with a nitinol shape-memory wire heated by an external power supply — a reminder that locomotion and sensing are still separate systems in this demo.

“You can, of course, use a ready-made photodiode, but you’d have to know quite precisely where to put it,” Pankratov said. “Growing the receptor on site means the environment itself can pattern the robot, based on what is actually happening at that time.” In the published work, researchers still decide when to fill the veins and where the stencil opens; the environment is not yet in charge.

By the numbers: a circulatory proof of concept

The sensor remained functional after four months in storage and grew more sensitive with repeated exposures as leftover pyrrole kept reacting, though each flash needs about five minutes to settle. The reaction is irreversible with the current chemistry. Pankratov told New Atlas that the real limit is how much of the body both fluid and light can reach, and that future systems might flush and reuse the veins with the same mix or a different one.

Where this sits among self-building robots

Robots that heal or extend themselves are not new. Cornell showed a soft robot that detected damage and repaired optical sensors in 2022; IIT’s FiloBot prints body material as it climbs; Cornell’s 2025 “robot blood” stored energy for jellyfish- and worm-like soft bots. The Tartu moth’s twist is receptogenesis — adding a sensing function the machine never shipped with — by using circulation as a chemical delivery system.

That idea maps to missions where packing every possible sensor is impossible: collapsed buildings, disaster rubble or planetary surfaces where lighting and hazards change after launch. A ready-made photodiode has to be placed in advance; a growable receptor could, in principle, form where ultraviolet or another cue actually appears. Related robotics coverage on TBR includes our Boston robotics roundup and the region’s Suffolk AI and robotics hub, while space-facing autonomy stories often sit near Science coverage.

What would have to change for field use

Pankratov said that in 10 years she hopes artificial robot blood and circulatory systems will be an “obvious choice” for some applications, with several material systems as state of the art. Reaching that bar means reversible or flushable chemistries, onboard decisions about when to pump, energy harvested from the fluid itself, and bodies large enough for fluid and light to reach useful sites. Batteries for the wings are doable; putting energy in the blood is the more interesting long-term path the team has begun testing.

For now, the moth is a lab demonstrator with clear numbers: roughly 3 milliliters of circulating feedstock, a 0.01-millimeter seep, a sensor that survives four months on the shelf, and a five-minute recovery after each UV flash. Those figures will not put soft robots into rubble tomorrow. They do show that a robot’s plumbing can grow hardware, not only move it.

Sources

• New Atlas: Robot moth grows new sensor using its own blood
• arXiv HTML: Receptogenesis in a Vascularized Robotic Embodiment
• Interesting Engineering: Robotic moth grows its own sensors with UV light and artificial blood
• Advanced Science: Receptogenesis in a Vascularized Robotic Embodiment (abstract)