This is a very good question, and depending on your year in school, a very timely one as well as applications to PhD programs are due relatively soon. Typically, in industry, the researchers who have PhDs are given the greatest amount of freedom, both in selecting and in managing their projects. Additionally, these researchers will also manage other researchers who will typically have bachelors or technical degrees. However, this freedom is not dependent on the field of engineering that you choose. In fact, to develop a truly innovative product, industry often brings together teams of engineers from different disciplines. For example, one of my colleagues who has a PhD and who works in the biotech industry manages a project which focuses on developing a new type of implantable device. These colleague and her co-workers have PhDs in bioengineering, electrical engineering, chemical engineering and mechanical engineering. I have other colleagues who work in the defense industry and who oversee the development of unmanned or robotic ground vehicles. These colleagues have PhDs in mechanical engineering, civil engineering, electrical engineering, and applied mathematics. If you think you might be interested in engineering, I would recommend participating in research in an engineering research lab at your school. Getting hands-on experience will help you decide if engineering is right for you and, if you decide to go to graduate school, it will strengthen your application. Best of luck!
Andrea M Armani