Luis Sentis with robot
Associate professor Luis Sentis presents the HCRL/Apptronik Draco Leg, a joint effort between UT Austin and Apptronik Systems, at the Office of Naval Research Science and Technology Expo.

Science fiction has long envisioned humans getting assistance from robotic helpers. Associate professor Luis Sentis is bringing to life two of the most well-known kinds: mechanical suits that boost the wearer’s physical strength and humanoid robots that can lend a hand on missions to other planets.

This summer, Sentis received research grants from the National Science Foundation and the Department of Defense to create the robotic devices. The NSF grant funds the development of humanoid robots that can prepare long-term living and work spaces on Mars or the moon ahead of human missions and then work alongside the astronauts when they arrive. The DoD grant supports research into strength- and speed-enhancing exoskeletons that feel second nature to the person strapped into the suits.

As the director of the UT Human Centered Robotics Group, Sentis’ work is grounded in creating robotic devices with humans in mind. The robots created by the group are intended to directly assist people and easily communicate with them.;

“Our work enhances the productivity of people,” Sentis said. “Their comfort, health, security and output — there is always the human factor.”

Sentis has plenty of prior experience creating robots that do just that. In 2013, he helped NASA design and test Valkyrie, an experimental humanoid robot with a superhero-like appearance built to move and maneuver around obstacles. He worked with engineering students to build Dreamer, a multi-purpose robot with blinking cartoonish eyes meant to attract and engage people. And in 2017, his team took third place in the RoboCup@Home, an international competition held in Nagoya, Japan, that tests robots’ domestic skills, from stocking a kitchen pantry to recognizing and greeting team members.

RoboCup winning team photo
In 2017, Dr. Luis his team took third place in the RoboCup@Home, an international competition held in Nagoya, Japan, that tests robots’ domestic skills, from stocking a kitchen pantry to recognizing and greeting team members.

The robot that Sentis is developing to prepare astronaut habitats will have to be more than a good housekeeper. By the end of the four-year grant, Sentis hopes to have a robot that can drive a rover, install solar panels, open a hatch and plug in electronics. He added that the humanoid form of the robot will endow it with more flexibility in mobility than robots with more specialized parts. 

Getting the robot to move fluidly will involve making the most of its powerful actuators that physically move the machine’s limbs. NASA’s Valkyrie robot uses a type of series-elastic actuators developed by Sentis’ research group on various parts of its limbs. Sentis said he envisions using artificial intelligence and similar actuator control systems to make space robots productive, safe and energy efficient for future exploration of extraterrestrial planets.

Advanced actuator technology is also at the heart of building an improved exoskeleton, Sentis said. A new type of actuator developed by Sentis and collaborators, called a liquid-cooled viscoelastic actuator, will help the exoskeleton be more responsive and lightweight, solving a major problem in current exoskeleton design: clunky and delayed movement.

“When people use them, they feel they’re working on crutches… at the end of the day you are more tired,” Sentis said. “So we’re going to deliver a new iteration of this type of technology, that’s focusing on what people want to wear without losing bodily dexterity or feeling uncomfortable.”

Exoskeletons that feel more natural could boost the performance of people who work physical jobs, from manufacturing and health to transportation and defense. But Sentis said he thinks that the biggest group to benefit from exoskeleton technology might be people with impaired or limited mobility. He said the future of exoskeletons may look less like an advanced Iron Man and more like robot-assisted grandparents walking with their grandchildren outdoors. 

“People are living to 85 and 95, so we’re going to see older people who need help walking,” Sentis said. “Exoskeletons will have huge applications.”