If you watched HBO’s ‘Westworld’ earlier this year, you probably remember the scenes where the nascent humanoid robots were strung up on circular frames like Leonardo da Vinci’s ‘Vitruvian Man,’ with machines printing white muscle fibers onto their skeletons. While the process of constructing androids doesn’t quite resemble this sci-fi vision just yet, it’s surprisingly close, especially with a new breakthrough in synthetic muscle tissue announced by researchers at Columbia Engineering. Their tests show a bundle of white muscle held in the palm of a researcher’s hand, moving and expanding in response to low power sent through a thin resistive wire.

This self-contained ’soft actuator’ is three times as strong as natural muscle, so yes, it’s true: Skynet is going to kill us all. The creators took inspiration from living organisms, using a silicone rubber matrix with ethanol distributed through micro-bubbles to simulate muscle tissue. It’s capable of expanding up to 900% when electrically heated to 80 degrees celsius, and can perform all sorts of motion tasks when controlled by computers.

“We’ve been making great strides toward making robots minds, but robot bodies are still primitive,” says Hod Lipson, Professor of Mechanical Engineering at Columbia and leader of the project. “This is a big piece of the puzzle, and, like biology, the new actuator can be shaped and reshaped a thousand ways. We’ve overcome one of the final barriers to making lifelike robots.”

“Our soft functional material may serve as robust soft muscle, possibly revolutionizing the way that soft robotic solutions are engineered today,” adds Aslan Miriyev, a postdoctoral researcher in the Creative Machines lab and lead author of the study ‘Soft Material for Soft Actuators,’ published by Nature Communications. “It can push, pull, bend, twist and lift weight. It’s the closest artificial material equivalent we have to a natural muscle.”