Programmable magnetized pillars enabled self-powered, single-channel and identity identifiable handwritten e-skin

Human–machine interaction (HMI) interfaces capable of conveniently transmitting massive human-made information and conversely recognizing the identity (ID) of individuals are highly desired while remaining challenging. Herein, a programmable self-powered handwritten e-skin consisted of soft magnetized pillars (MPs) and an underneath flexible coil electrode for convenient, efficient and ID identifiable HMI applications is presented. With the built-in magnetic moment alignment, the deflection and elastic recovery (ER) of the soft MPs triggered by sliding operations can induce the sequential generation of sliding-adaptive negative voltage signals and fixed ER-induced positive voltage signals. The sliding-adaptive signals can originally serve as the bio-mechanical information of individuals to recognize the habit-related sliding speeds for ID identification. The sliding-irrelevant ER-induced signals can be further programmed into a variety of non-overlapping levels by customizing the MPs with different elastic and magnetic properties. Such programmable non-overlapping ER-induced signals not only ensure the capability of encoding massive information, but also endow the function of single-channel addressing of the e-skin. With these distinctive features, the potential applications of high-capacity commands output for game character controlling, single-channel handwritten transmission of alphabet information, and password/ID dual decoding (with an average accuracy rate of 99.5%) are successfully demonstrated.