A Tunable Morphing Polyelectrolyte System for Smart Ocular Applications

For the first time, a focal-length tunable intra-ocular lens (IOL) device has been realized by a standard-shaped, homogeneous “one material” system. Different to existing technologies, this poly(N-isopropylacrylamide) gel (PNIPAM) based polyelectrolyte system doesn't require any additional materials (e.g. metal electrodes, movable mechanical structures) to achieve a controllable lens shape transformation for the focal-length shifting actuation. The designed morphological deformation mechanism employs ionic-strength responsive mechanical buckling via controlled swelling of PNIPAM in phosphate buffered saline (PBS) with similar concentration to human eye liquid. This unique approach will unlock great potential in a wide range of smart ocular applications.