Smaller computing chips may depend on technology from grandma's radio

Pasadena, California

THE future of computing may be in its past.

The silicon transistor, the tiny switch that is the building block of modern microelectronics, replaced the vacuum tube in many consumer products in the 1970s. Now, as shrinking transistors to even more Lilliputian dimensions is becoming vastly more challenging, the vacuum tube may be on the verge of a comeback.

In a darkened laboratory …