The Defense Department's chief technology official has expanded the list of critical areas for research and engineering in a gambit to "drive innovation" to new sectors such as renewable energy generation -- a push to enlarge the U.S. military technology development portfolio even as inflation is threatening to squeeze Pentagon investment plans. On Feb. 1, Heidi Shyu, under secretary of defense for research and engineering, issued a six-page memo -- not previously reported -- outlining her “technology vision for an...