Mars robots mimic inchworms for traction

Planetary robots usually look like small tanks. Wheels, rigid joints, careful suspension, lots of control logic. That works — until the ground gets too loose, the rocks get too awkward, or the robot needs to keep going after a puncture. The new thing here is a soft crawler from the University of Gothenburg, backed by ESA, that borrows its movement from an inchworm instead of a rover. ESA put the project in the spotlight on May 11, framing it as a possible way to move across Mars- or Moon-like terrain with less hardware and more resilience. ### Why copy an inchworm? Because inchworms do a very simple trick extremely well. They shorten, anchor, extend, and pull the rest of the body forward. That matters on rough ground where a wheel can just spin in place. The robot uses that same basic idea — not legs stepping over obstacles, not tires digging for grip, but a body that changes shape and inches ahead by controlled contraction and extension. (esa.int) ### What is the robot actually made of? The core part is a rolled dielectric elastomer actuator, or RDEA. Basically, that is an artificial muscle made from a thin flexible polymer with compliant electrodes around it. Apply voltage and the structure deforms. In this design, the rolled actuator contracts and extends along its length, which gives the robot its inchworm-like crawl without traditional motors and rigid linkages. (esa.int) ### Why is that useful on Mars? Mars is hard on machines in two different ways at once. The terrain is irregular, sandy, rocky, and unpredictable. The environment also punishes electronics and materials with radiation, temperature swings, and zero maintenance opportunities. A soft robot helps with the first problem because it can conform to uneven surfaces and squeeze through tighter spaces than a rigid rover. This design also tries to help with the second problem by reducing mechanical complexity — fewer hard joints, fewer conventional moving parts, fewer things to jam or crack. (esa.int) ### What is the radiation angle? This is the part that makes the project more than a cute bio-inspired demo. The actuator’s electrodes use single-walled carbon nanotubes, and the team says experiments and simulations showed fault-tolerant behavior plus partial shielding against simulated Martian alpha and proton radiation at 10 MeV. ESA’s write-up also says the actuator can keep functioning even when partly cut or punctured. That is a big deal for planetary hardware, where “still works after damage” is often more valuable than “works perfectly in the lab.” (esa.int) ### Does it need lots of steering hardware? Turns out, no — that is one of the main goals. The Gothenburg team was trying to get multidirectional movement in a soft robot without piling on extra actuators and complicated electronics. That matters because every added subsystem costs mass, power, and reliability margin. If the body and terrain interaction do more of the work, the robot can stay simpler. (esa.int) ### Is this replacing rovers soon? Probably not. This looks more like a new mobility option than a wholesale rover replacement. Wheels are still efficient on a lot of terrain, and space agencies know how to fly them. But the gap is obvious — loose regolith, narrow gaps, damaged hardware, and weird surfaces where classic rover geometry becomes a liability. Soft crawlers could fill those edge cases, or work as companion robots sent into places a bigger rover should avoid. (esa.int) That last part is an inference, but it fits the mission logic ESA is pointing at. ### So what changed this week? The concept moved from generic soft-robotics research into a clearly framed planetary-exploration story. ESA publicly highlighted the project, named the University of Gothenburg team, and tied the design to Mars and Moon use cases, radiation tolerance, and low-power operation on May 11, 2026. That turns it from “interesting lab mechanism” into “serious candidate idea for off-world mobility.” (esa.int) ### Bottom line? The clever part is not just that it crawls like an inchworm. It is that the same soft body may also survive the exact kinds of punishment that make extraterrestrial robots fail. (esa.int)