Kevin Albert is playing the part of lion tamer. The 33-year-old engineer, with a passing resemblance to Joe Namath, sticks his head into the four-fingered grip of a robotic hand, pauses for a moment and then emerges unscathed.

This is no ordinary robot: It's made of fabric and air rather than steel and motors. Albert, co-founder of the San Francisco startup Pneubotics, is demonstrating how a new generation of robots can be made safer and more versatile — allowing them to move off the factory floor and work in close proximity with humans.

Though the robot population has risen to 1.6 million since General Motors Co. first put one on an assembly line in 1961, growth has been limited because most are variations on the original theme, dangerous claw attached to metal limb. Companies like Pneubotics are creating alternatives that, if they work, could bring the productivity of robots to more industries, including construction, warehousing and agriculture.