Renowned chemical engineer Robert Langer, a pioneer in the development of the mRNA vaccines used to help combat COVID-19, will speak Wednesday, June 1, at 7:30 p.m. in the Nott Memorial. His talk, “From Nanotechnology to mRNA Vaccines: How Overcoming Skepticism and Barriers Led to New Cancer Treatments and Ways to Tackle a Global Health Challenge,” is free and open to the public.