CAMBRIDGE, Mass.--(BUSINESS WIRE)--Today, The Engine, the venture firm spun out of MIT that invests in early-stage Tough Tech companies that are solving the world’s most urgent problems, announced the appointment of Susan (Sue) E. Siegel as its new Chairman of the Board of Directors. With more than three decades of senior executive experience across corporate, entrepreneurial and venture capital, Siegel will assume the role from Israel Ruiz, former EVP and Treasurer of MIT, who is stepping down.