Structural flexible magnetic films for biometric encryption and tactile interaction in wearable devices

Human fingers have fingerprints and mechanoreceptors for biometric information encryption and tactile perception. Ideally, electronic skin (e-skin) integrates identity information and tactile sensing, but this remains challenging. Research on encryption and tactile sensing rarely overlaps. Here, we report using magnetization structures and combinations of magnetic materials to achieve two types of functions: 6^{n × n} invisible secure encryption is achieved through a n × n dipole magnetic array, and multipole magnets are used to achieve decoupling of pressure at various positions and sliding in different directions. The sliding distance ranges from 0 to 2.5 mm, with speeds between 5 and 25 mm/s. This study is based on flexible magnetic films, which have the potential to be used in wearable devices. The magnetic ring and signal detection modules verify the prospects of this fundamental principle in human-computer interaction (HCI) and demonstrate its applications in user identity recognition and tactile interaction.