Advanced tactile feedback systems are important tools in the field of human–machine interfaces. In this work, an airflow-assisted corona charging process is utilized to charge films made of electret material for the construction of a sandwich-structured flexible actuator system. With a voltage as low as 20 V, this flexible actuator can stimulate skin sensations for basic tactile feedback functions. Under a driving voltage of 200 V, the system can generate an output force of ≈55 mN, which is larger than that of the output force by cellphones under the vibration mode. Utilizing these prototype flexible electret actuators array, programmable patterns of tactile sensations can be generated on human skin according to both vibrational intensities and spatial positions. Thus, two demonstrations of human–machine interface are illustrated based on the proposed device: 1) A tactile-assisted navigation prototype with programmable commands; and 2) a tactile-based braille prototype constructed via a 6-pixels actuator array to generate designated patterns for assisting human–machine communications. As such, this system prototype has potential for applications in cognitive assistance via tactile feedbacks.
Keywords: Tactile feedback, Cognitive assistance, Actuator, Electret