The photomodulation of the helical pitch of cholesteric liquid crystals results in dynamic and coloured canvases that can potentially be used in applications ranging from energy-efficient displays to colour filters, anti-counterfeiting tags and liquid crystal (LC) lasers. Here we report on the analysis of a series of photoswitchable chiral dopants that combine the large geometrical change and bistability of hydrazone switches with the efficient helical pitch induction of the chiral motif, triptycene. We elucidate the effects that conformational flexibility, dispersion forces and π–π interactions have on the chirality transfer ability of the dopant. We then use the irradiation time with visible light (442 nm) combined with a simple digital light processing microscope projection set-up to draw numerous stable multi-coloured images on an LC canvas, showcasing the fine control this dopant yields over the LC assembly.

胆甾型液晶螺距的光调制可产生动态的彩色画布，可​​用于从节能显示器到滤色器、防伪标签和液晶 (LC) 激光器等各种应用。在这里，我们报告了一系列光开关手性掺杂剂的分析，这些掺杂剂将腙开关的大几何变化和双稳定性与手性基序三蝶烯的有效螺旋螺距诱导相结合。我们阐明了构象灵活性、色散力和 π-π 相互作用对掺杂剂手性转移能力的影响。然后，我们利用可见光 (442 nm) 的照射时间与简单的数字光处理显微镜投影装置相结合，在液晶画布上绘制大量稳定的多色图像，展示了这种掺杂剂对液晶组件的精细控制。