Fabrication and performance of programmable light driven soft actuators for character displays

Soft actuators hold significant promise for applications in the display field, yet their complex programmability and low display accuracy limit their development in this area. In this paper, a programmable dual-layer character soft actuator based on ink and polydimethylsiloxane (PDMS) was prepared by utilizing the different coefficients of thermal expansion (CTE) between the two materials. By programming the initial shape of the soft actuator, it can bend under near-infrared (NIR) light irradiation to accurately exhibit specific characters. The optical and mechanical performance of this actuator was tested, revealing its capability to achieve a large-angle bend of nearly 90 degrees within 30 s and revert to its initial state within 20 s. The actuator demonstrates programmability, fast response, rapid recovery, and good repeatability. The study found that the temperature and degree of bending of the actuator are closely related to the power of the NIR light. Additionally, different programmable character soft actuators were designed through cutting and assembling methods, enabling precise transformation into pre-designed characters under NIR light exposure. By applying the designed character soft actuator to teaching, the near infrared light is used to make one kind of letter turn into another kind of letter, so as to achieve the purpose of teaching demonstration. [Display omitted] •The programmable character soft actuators driven by near-infrared light was studied.•Character changes was realized by cropping the soft drive.•The actuator showed fast response, rapid recovery, and good repeatability.•Applying programmable character soft actuators to teaching and learning.