A magnetic artificial cilia platform for dynamic mechanical stimulation of cells.

Mechanical forces play a key role in regulating cell behaviour, with dynamically changing mechanical cues governing processes such as morphogenesis, wound healing, and cancer progression in vivo. However, there is a lack of experimental platforms that enable localized, dynamic, and tuneable mechanical stimulation under real-time imaging. Here, we present a large deflection magnetic artificial cilia (ldMAC) platform that enables dynamic, microscale mechanical stimulation of cells with high spatial and temporal control. Arrays of ldMAC are fabricated via femtosecond lasermachining and hot embossing of a magnetic polymer, yielding robust ldMAC capable of tip deflections up to 25 μm under actuation by a custom-made, compact permanent magnet-based system, representing a several-fold increase in displacement compared to most reported magnetic pillar platforms. The setup is compatible with standard cell culture conditions and live fluorescence microscopy, a feature that is typically challenging due to the bulky and complex nature of conventional actuation systems. Using human dermal fibroblasts, we demonstrate that ldMAC actuation induces changes in cell morphology without affecting viability. Dynamic stimulation by cyclic ldMAC deflection leads to a shift toward more compact, rounded cell phenotypes, accompanied by reduced cell area. Time-lapse imaging reveals that cells actively reorganize cytoskeletal structures and reduce the amount of cilia attachments upon stimulation, reminiscent of strain avoidance behaviour. Compared to existing approaches, the presented platform uniquely combines localized, dynamic, controllable actuation with real-time imaging in a compact, user-friendly format. Importantly, it enables active and reversible ldMAC deformation with independently tuneable frequency and amplitude. This approach offers a practical tool for studying cellular responses to dynamic mechanical environments and opens new possibilities for mechanobiology research.