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Sliman Bensmaia, who added sensations of touch to prosthetics, dies at 49

He was an instrumental figure in helping amputees and paralyzed patients feel textures, temperatures and shapes through bionic devices.

Sliman Bensmaia in 2014 at the University of Chicago. (Jason Smith/University of Chicago)
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Sliman Bensmaia, a trailblazing neuroscientist working on brain computer interfaces allowing amputees and paralyzed patients to control prosthetic and robotic limbs while simultaneously feeling the natural sensations of touch, died Aug. 11 at his home in Chicago. He was 49.

The University of Chicago, where Dr. Bensmaia was a professor of organismal biology and anatomy, announced his death but did not cite a cause.

Dr. Bensmaia and his collaborators created algorithms that mimic the biological processes of how the brain interacts with limbs to generate sensations of touch. Then they implanted electrodes in the brain that connected to sensors on bionic hands.

The feel of textures, temperatures and shapes reappeared almost like magic — surprising not just patients, but Dr. Bensmaia.

After joining a Defense Department effort 15 years ago to make prostheses more lifelike for wounded warriors, Dr. Bensmaia doubted that he and other scientists would ever get as far as they did in mimicking the sensations of touch.

“I imagined it was not going to be possible,” he told “60 Minutes” earlier this year. “There are 100 billion neurons in the brain interconnected with 100 trillion synapses. I mean, the human brain, it’s like the most complex system in the known universe.”

Dr. Bensmaia and his colleagues began their research with monkeys, identifying neural activity patterns that occurred when they manipulated objects. The researchers were able to re-create those patterns in computer algorithms, then worked with engineers to create the devices.

In 2016, collaborating with researchers at the University of Pittsburgh, Dr. Bensmaia developed a robotic prosthetic arm for Nathan Copeland, a man paralyzed from the chest down following a car accident.

Copeland was able to control the arm and hand with his thoughts, and he was able to feel sensations in his fingers and palm. The device itself was not physically attached to his torso. Copeland fist-bumped President Barack Obama during a demonstration of promising scientific breakthroughs at the University of Pittsburgh.

“That is unbelievable,” Obama said. “Nathan is moving his hand with his brain.”

Sliman Julien Bensmaia was born in Nice, France, on Sept. 17, 1973. His mother and father are philosophers.

He moved to the United States as a teenager, graduating from the University of Virginia in 1995 with a bachelor’s degree in cognitive science.

In 2003, he received a doctorate in cognitive psychology with a minor in neurobiology from the University of North Carolina at Chapel Hill. He then joined the Zanvyl Krieger Mind/Brain Institute at Johns Hopkins University as a postdoctoral fellow and associate research scientist.

Dr. Bensmaia left Hopkins for the University of Chicago in 2009. He ran a large lab that employed engineers alongside cognitive scientists. His laid-back personality and style was refreshing, his colleagues recalled.

“He was not formal at all,” Nicholas Hatsopoulos, a colleague and collaborator at the university, said in an interview. “He always wore superhero T-shirts. He did not like dressing up formally. And he swore like a sailor, but not in a mean way. That’s just the way he spoke.”

Dr. Bensmaia married Kerry Ledoux, a University of Chicago psychology professor, in 2007. In addition to his wife, survivors include two children, Cecily and Maceo Bensmaia; his parents; and a brother.

In addition to his work with amputees and paralyzed patients, Dr. Bensmaia was working with Stacy Lindau, a University of Chicago gynecologist, on a bionic breast for cancer patients who had undergone mastectomies.

“Sliman’s passion for restoring the human sense of touch had its origins in love,” Lindau said in the announcement of Dr. Bensmaia’s death. “He was drawn to the Bionic Breast Project because of the potential for very large-scale impact of his discoveries and because he saw uncharted territory in the scientific understanding of loving touch, specifically.”


A previous version of this article misstated the first name of Dr. Sliman Bensmaia. The article has been corrected.