Equipped with giant padded arms, Robear is the latest in a line of prototype nurse robots designed to take on some of the backbreaking work of caregivers who must lift patients an average of 40 times per day in Japan, which has a rapidly greying population.
In contrast to the earlier prototypes Riba and Riba II, Robear is capable of gentler movements because it has capacitance-type tactile sensors that feed data to its actuators, which in turn can quickly sense any resistance to exerted force from patients' bodies.
The tactile sensors are based on auto parts maker Sumitomo Riko's Smart Rubber, a flexible rubber sensor that can measure pressure and deformation. The robot also has six-axis torque sensors, cameras, a microphone and 27 degrees of freedom, or axes of motion.
At 140kg, the 1.5-metre-tall Robear is 90kg lighter than Riba II, unveiled in 2011. Engineers gave it a smaller base with retractable legs that can be deployed for stability during lifting operations. The legs can be stowed to move the robot around.
The droid still requires human control, however -- either by manually guiding its arm or via a linked Android tablet -- and its lifting capacity is still only 80kg. It can operate for about four hours on a charge of its lithium-ion batteries.
Though Robear comes from a line of nurse-bot prototypes going back to Ri-Man in 2006, Riken is not aiming to commercialize the machine itself. Instead it hopes the technologies could go into a practical nursing-care robot.
"For commercialisation in the near future, we need much simpler, lower-cost robots," Robear project leader Toshiharu Mukai said via email. "For example, the number of motors should be reduced to two or three and the price should be lower than ¥50,000 (£275)."