Growing up in London, Michelle's interests frequently bumped up against expectations of girls which she pushed through, including her love of playing soccer and chess, and later, her passion for science and technology. Professor Simmons is well-known for creating the field of atomic electronics. Since 2000 she established the Centre of Excellence for Quantum Computation and Communication Technology dedicated to the making of tiny atomic-scale devices in silicon and germanium. Her research group at the University of New South Wales is the only group worldwide that can create atomically precise devices in silicon. It was also the first team in the world to develop a working 'perfect' single-atom transistor and the narrowest conducting doped wires in silicon.

In 2018 Michelle became Australian of the Year and is an Australian Research Council Laureate Fellow. She is passionate about encouraging girls to pursue a career in science and technology: 'Seeing women in leadership roles and competing internationally ... gives them the sense that anything is possible'.