Topologically Protected Twist Edge States for a Resonant Mechanical Laser-Beam Scanner

Topological band gaps lead to protected edge states and robust transport in electronics, photonics, and even mechanics. In this work, the authors design a one-dimensional mechanical topological band gap hosting a protected twist edge state, using a simple, analytical mass-spring model and finite-element simulations of a three-dimensional chiral beam microstructure. Such a beam can transform a small push-pull excitation at the one end (provided by $e.g.$ a piezoelectric transducer) into a large rotation at the other end. The system could potentially be utilized as a high-frequency resonant mechanical laser-beam scanner.