Soft Is the New Strong

A stream of discarded batteries races down a conveyor belt.

AAA cells tumble alongside bulky power tool packs. Old phone batteries slide past laptop bricks. No order. No separation. Just speed, volume, and constant motion.

For now, human hands keep up with the chaos.

Gaurav Singh sees a different future.

Singh, assistant professor in the A. Leon Linton Department of Mechanical, Robotics, and Industrial Engineering within LTU’s College of Engineering, is developing a robotic system that can step into that moment.

Not with rigid metal or mechanical claws, but with something softer.

Something that adapts.

A Different Kind of Machine

“This is really about making recycling more efficient and more sustainable,” Singh said. “Right now, sorting is a manual process. We’re trying to automate that in a way that is both effective and safe.”

At the center of his work is a soft robotic gripper designed to do what traditional robots struggle with: handle variation. Respond in real time. Touch without breaking. Instead of steel, the gripper is made from silicone and other flexible materials. Instead of hinges and joints, it relies on air. Inside each finger are hollow channels. When pressurized, they expand and bend, curling inward in one smooth motion. The movement is continuous, not mechanical. More like a hand closing than a machine activating.

Built to Adapt

“If you look at humans or animals, we have a skeleton, but we are surrounded by soft components like muscles and skin,” Singh said. “We’re taking that idea and applying it to robotics.”

The effect is subtle but powerful. The gripper does not need to be told exactly how to grab every object. Its structure allows it to adapt on contact.

“It’s almost like a balloon, but designed in a way that it bends exactly how we want it to,” Singh said.

That adaptability is critical in battery recycling, where no two items are quite the same. A AAA battery requires a completely different approach than a dense, irregular power tool pack. Designing a single system that can handle both is not a small task.

“We’re trying to figure out how one design can adapt to that range,” Singh said.

From Lab to Prototype

The current version of the gripper was developed by Kevin Campbell, an LTU master’s student in Mechanical Engineering, whose earlier work focused on picking up thin, flat objects like coins and cards. That work laid the foundation for a system capable of handling far more complex tasks.

“Kevin designed and built this version of the gripper,” Singh said.

In Singh’s lab, students are not just observing research. They are conducting it. Casting components, testing designs, running experiments, and learning how to work with materials that behave very differently from anything they have used before.

Each gripper begins as liquid silicone poured into a mold. It cures slowly. Then comes the careful work of removing it without tearing. A small flaw can lead to air leaks. Failure is common. Progress is earned.

The Hard Part About Soft

“It’s not just a process,” Singh said. “There’s a level of craftsmanship to it.”

That challenge extends beyond fabrication. Unlike steel or aluminum, soft materials are harder to predict, especially over repeated use.

“These materials are relatively new in engineering,” Singh said. “We are still learning how they behave over long periods and many cycles.”

The team is now testing how well the gripper performs across a range of battery types, tracking what works, what fails, and why. That data will shape the next iteration. More fingers. Different configurations. New approaches to motion.

Battery sorting is the starting point. Not the destination.

Beyond Recycling

What Singh is really building is a different way to think about robots. Machines that do not rely on brute strength or rigid precision. Machines that are designed, from the ground up, to interact more naturally with the world around them.

“We want robots that are not just powerful, but safe by design.”
– Gaurav Singh, assistant professor

“There’s a real opportunity to create robots that are safer and more compatible with human environments,” Singh said.

That shift matters beyond the lab.

As populations age and demand grows for in-home support, the need for machines that can assist without risk becomes more urgent. A robot that can lift, move, or help without the threat of harm changes what is possible.

Singh sees a future where robots are not just tools, but companions in daily life. Present in homes, in care settings, in the spaces people live and work.

Not hard. Not intimidating. Not distant.

“We want robots that are not just powerful, but safe by design,” he said. “That’s the future we’re working toward.”

And it starts with something as simple, and as complex, as a softer grip.