Plextronics, Inc. announced that Dr. Robert Kumpf has joined the company as chief operating officer, a role in which he will lead the company’s manufacturing and engineering operations with a focus on scaling capacity to meet increasing customer demand.     Dr. Kumpf comes to Plextronics after a 25-year career at Bayer MaterialScience where he most recently served as Bayer MaterialScience’s chief administrative officer.     During his tenure at Bayer, he also held executive leadership roles ...