Halogen-Assisted Piezochromic Supramolecular Assemblies for Versatile Haptic Memory

Sensory memory is capable of recording information and giving feedback based on external stimuli. Haptic memory in particular can retain the sensation of the interaction between the human body and the environment and help humans to describe the physical quantities in their environment and manipulate objects in daily activities. Although sensitive and accurate tactile sensors have been produced on optical and electronic devices, their rigorous operation and equipment requirements seriously limit their further applicability. In addition, their poor retainability after the removal of external stimuli also warrants further improvements. Thus, haptic memory materials, having simple structures and high sensitivity, are highly desired. Herein, we successfully developed two piezochromic assemblies assisted by halogen bonding for haptic memory. The halogen bond not only contributes to the fabrication of the network and enhances integrative stability but also broadens the natural piezofluorescent range, thus promoting sensory sensitivity. Moreover, the colorimetric change of the assemblies could be well-retained after the stimulus was removed. Upon mild heating treatment, the piezochromic response could be recovered to its original state, confirming the recyclability of this haptic memory material for use in practical applications. The present work enriches the library of piezochromic materials with enhanced performance for haptic memory.感觉记忆（sensory memory）能够记录信息，并基于外部刺激给出反馈。具体而言，触觉记忆（haptic memory）可保留人体与环境交互时的感知，帮助人类感知周遭环境的物理量，并在日常活动中操控物体。尽管基于光学与电子器件已制备出灵敏度与精度俱佳的触觉传感器，但其严苛的操作条件与设备要求严重限制了其进一步的应用拓展。此外，这类传感器在外部刺激移除后感知留存能力不足的问题，同样有待进一步优化。因此，具备简易结构与高灵敏度的触觉记忆材料成为当前的迫切需求。本研究中，我们成功开发出两种基于卤键（halogen bonding）辅助制备的压致变色组装体，用于触觉记忆应用。卤键不仅有助于构建网络结构、提升整体稳定性，还拓宽了本征压致荧光的响应范围，进而增强了感知灵敏度。此外，该组装体的颜色变化可在外部刺激移除后得到良好留存。经温和热处理后，其压致变色响应可恢复至初始状态，证实了该触觉记忆材料具备可循环复用性，可满足实际应用需求。本研究丰富了面向触觉记忆应用的高性能压致变色材料库。