Metal ion-responsive photonic colloidal crystalline micro-beads with electrochemically tunable photonic diffraction colours

This work reports a metal ion-responsive photonic colloidal crystalline (PCC) microspheric material and the convenient, reversible switching of its photonic diffraction properties by the redox reaction of copper in a simple electrochemical cell. This concept of rapid electrochemical regulation of photonic diffraction colour of PCC micro-beads may be useful as pixels in reflective displays applications.