Magnetized Micropillar-Enabled Wearable Sensors for Touchless and Intelligent Information Communication

Abstract

The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception, decoding, and conveying process. However, it is still challenging to obtain a sensor that can convert detectable signals into multiple outputs for convenient, efficient, cryptic, and high-capacity information transmission. Herein, we present a capacitive sensor of magnetic field based on a tilted flexible micromagnet array (t-FMA) as the proposed interaction interface. With the bidirectional bending capability of t-FMA actuated by magnetic torque, the sensor can recognize both the magnitude and orientation of magnetic field in real time with non-overlapping capacitance signals. The optimized sensor exhibits the high sensitivity of over 1.3 T−1 and detection limit down to 1 mT with excellent durability. As a proof of concept, the sensor has been successfully demonstrated for convenient, efficient, and programmable interaction systems, e.g., touchless Morse code and Braille communication. The distinguishable recognition of the magnetic field orientation and magnitude further enables the sensor unit as a high-capacity transmitter for cryptic information interaction (e.g., encoded ID recognition) and multi-control instruction outputting. We believe that the proposed magnetic field sensor can open up a potential avenue for future applications including information communication, virtual reality device, and interactive robotics.

Breathable and Waterproof Electronic Skin with Three-Dimensional Architecture for Pressure and Strain Sensing in Nonoverlapping Mode

“…Morse code is a reliable and mature communication technology by way of encoding information ( e . g ., letters or numbers) with standardized sequences of “dots” and “dashes”, which has also been widely demonstrated based on flexible and wearable sensors. , The flexible device can monitor tiny body signals and convert corresponding electrical outputs for Morse code generation, which enriches the communication channels especially for people suffering from general paralysis. Conventionally, the wearable devices are duration-regulated, in which the user controls the duration of the mechanical stimuli for the signals of “dots” and “dashes”, as shown in Figure b.…”

“…As shown in Figure c, the ternary sensor can produce a resistance increase (Δ R > 0) or decrease (Δ R < 0) triggered by the applied strain or pressure, and the resultant nonoverlapping signals can be easily utilized as “dashes” and “dots” to encode messages. Via applying different mechanical stimuli, the nonoverlapping (positive and negative) electrical signals can correctly reflect the demand from the input terminal and ensure the accuracy of information when compared with the duration- or intensity-based definition. , Figure d shows the real-time generation of Morse code for “SOS” and “1234” by regularly touching and stretching the proposed sensor (see Video S6 for the complete signal generation process). When pressure was applied to the E-skin, a negative resistance variation was recorded and encoded as a “dot”, while a strain-induced positive resistance variation was defined as a “dash”.…”

“…For example, the traditional pressure sensor was considered as a binary converter that generates the signal “0” under the idle state and provides the signal “1” when mechanical stimuli were applied. , Thus, the command table with a capacity of 2 n could be provided by an array with n devices, as shown in Figure g. On the contrary, if the device could generate the ternary signals of “–1”, “0”, and “1”, the capacity could be increased to a broader capacity of 3 n if an array with n devices was built . Herein, we defined the output of the E-skin sensor as “1” (strain-triggered, Δ R > 0), “0” (idle status, Δ R = 0), and “–1” (press-triggered, Δ R < 0), respectively.…”

A phonic Braille recognition system based on a self-powered sensor with self-healing ability, temperature resistance, and stretchability

“…5e. 3,[7][8][9][10][52][53][54][55][56] The widely investigated piezoresistive and capacitive Braille recognition sensors are overwhelmingly dependent on the external power supply. 7,8,[53][54][55][56] The reported Braille recognition sensors are almost all composed of irreversible covalent bond-based polymer materials, such as polytetrafluoroethylene (PTFE), Kapton, and PDMS, 3,9,52 which could not be recovered once broken.…”

“…3,[7][8][9][10][52][53][54][55][56] The widely investigated piezoresistive and capacitive Braille recognition sensors are overwhelmingly dependent on the external power supply. 7,8,[53][54][55][56] The reported Braille recognition sensors are almost all composed of irreversible covalent bond-based polymer materials, such as polytetrafluoroethylene (PTFE), Kapton, and PDMS, 3,9,52 which could not be recovered once broken. Overall, the as-fabricated TENG-based self-powered, self-healing, temperature-resistant, and stretchable Braille recognition system with real-time auditory feedback is highly promising for the visually impaired and the blind to achieve better communication and learning.…”