Yet, the Tufts researchers point out, a caterpillar needs no postgraduate training before it begins to slink across a leaf. Remove the hornworm’s primitive brain, and it still trudges forward. So Dr. Trimmer suggests that much of the secret of locomotion is inherent in the muscles and the body. The hornworm has just 70 muscles per segment, with just one nerve controlling each muscle, for the most part. The researchers suspect that the wonderfully flexible locomotion of the caterpillar might emerge naturally from relatively simple rules.

The researchers are seeking a similar elegance in their creations. The initial creatures are hollow tubes. The “muscles” are wire springs made from shape-memory alloy. Electrical current heats the springs, causing them to constrict; once the current stops, the elastic skin stretches the wire back into its resting shape. “It’s almost childish, the simplicity of the design,” Dr. Trimmer says.

The skin is a silicone rubber that goes by the brand name Dragon Skin, and its composition can be manipulated so that it can be leathery-tough or so supple and clammy that it gives a sense of what it must be like to shake hands with Gollum. Eventually, the researchers hope to build on the work of David Kaplan, a Tufts professor of biomedical engineering who has pioneered the creation of tough, flexible materials based on spider silk so that the creatures would be largely biodegradable.

Aside from the dissected caterpillar on the table, there is just one other completed model, but it is inert, having pulled a muscle, as well as bits of squirmy this and that. The research, which is financed by the W. M. Keck Foundation, “is very preliminary,” Dr. Trimmer admits.

Image An earlier model of robotic caterpillar. Credit... James Estrin/The New York Times

The researchers have gotten a wave to propagate across a robot’s body; that wave picks up the feet in a way that already resembles the foot motion of a real caterpillar. By the end of the year, they hope to have robots capable of full locomotion that emulate the action of the caterpillars, he said. The puzzle of coming up with computer code to coordinate the movements, they suggest, will be greatly accelerated using the rapid trial-and-error approach that, in the world of computing, is called genetic algorithms.

They see a day when the cheaply built machines — less than a dollar apiece, Dr. Kaplan predicts — could be crammed into a canister and shot into a minefield. The hollow bodies would contain a simple power source and mine detectors; the caterpillars would wriggle across the terrain at random, stopping when they detect a likely mine. “There’s no need for high speed,” Dr. Kaplan said. “Slow and steady is fine.”