3D-Printing Enabled Reconfigurable Shape-Morphing Polyelectrolyte Systems For Smart Ocular Devices

Smart hydrogels with tunable mechanical properties have shown promising future in applications such as programmed cell hosting, 3D cell culturing and advanced tissue engineering. Recent progress in hydrogel micro-engineering has enabled active shape-morphing for a range of bio-inspired applications. In particular, the authors of this abstract have recently engineered reconfigurable and multi-scale hydrogel shape-morphing structures through 3D printing rapid-prototyping. By integrating shape-morphing mechanisms, it now becomes possible to realize re-configurable and scalable biomechanical stimulation, structural and mechanical gradience, closely mimicking functions of human eye system at different scales. This will unlock a set of new tools to empower smart ocular devices.

In this work, a shape-morphing intra-ocular lens (IOL) device with tunable focal length has been realized by a design-reconfigurable, homogeneous “one material” system through the help of 3D printing technologies. Different to existing technologies, this polyacrylamid gel (PAAm) based polyelectrolyte system doesn’t require any additional materials and structures (e.g. external actuator, metal electrodes) to achieve dynamic lens shape transformation. The designed actuation mechanism employs ionic-strength responsive mechanical buckling via controlled swelling of PAAm in phosphate buffered saline (PBS). This unique approach will unlock great potential in a wide range of smart ocular applications.

Configured shape-tuning has resulted focal length shifting as designed, demonstrated by both shape-profiling and optical characterization. The initial results coming from this concept which combines rapid-prototyping designs and “one material” approach has demonstrated clear potential in future smart ocular devices.