Jack Kilby, inventor of the integrated circuit, the basis of the computer chip revolution and foundation of what is now a trillion-dollar industry, died of cancer on Monday. Kilby, 81, made the discovery 47 years ago, when, as a recently hired engineer at Texas Instruments Inc., he was left to work alone in a laboratory while most of his 7,500 colleagues were taking a company-wide summer vacation leave. By hand-wiring together multiple transistors, Kilby’s invention