31 March 2021
Vol 6, Issue 52

About The Cover

Cover image expansion

ONLINE COVER Microrobotic Shapeshifters. Robust, fast, and low-power actuation at the microscale is necessary for the continued advancement of microrobotic systems. Liu et al. have developed a micrometer-sized shape-memory actuator that achieves reversible actuation and shape-memory effects through surface electrochemical reactions. These programmable shape-memory actuators have a radius of curvature of ~500 nanometers and an operation speed of less than 100 milliseconds and can be driven at voltages as low as 1 volt. This month's cover is a false-color scanning electron microscope image of an origami duck composed of microscale surface electrochemical actuators (see also the Focus by Omar et al.). [CREDIT: QINGKUN LIU/MCEUEN AND COHEN LABS/CORNELL UNIVERSITY]