Wearable and Semitransparent Pressure-Sensitive Light-Emitting Sensor Based on Electrochemiluminescence

Abstract

Tactile sensors are being researched as a key technology for developing an electronic skin and a wearable display, which have recently been attracting much attention. However, to develop a next-generation wearable tactile sensor, it is necessary to implement an interactive display that responds immediately to external stimuli. Herein, a wearable and semitransparent pressure-sensitive light-emitting sensor (PLS) based on electrochemiluminescence (ECL) is successfully implemented with visual alarm functions to prevent damage to the human body from external stimuli. The PLS is fabricated with a very simple structure using the ECL gel as the lightemitting layer and a carbon nanotube embedded polydimethylsiloxane as the electrode. The ECL light-emitting layer using a redox reaction is advantageous for the fabrication of nextgeneration wearable devices due to the advantages of a simple structure and the use of electrodes without work function limitation. The PLS can display various external stimuli immediately and operate at a high luminance, making it safe to use as a wearable sensor. Therefore, the PLS using ECL can be a simple and meaningful solution for next-generation wearable tactile sensors.

E-Skin: The Dawn of a New Era of On-Body Monitoring Systems

“…Nowadays, the e-skin sensors designed and developed measure physiological variables like heart rate, blood oxygen saturation, glucose, or moisture and display them. Moreover, the capabilities of transparent [182] or semitransparent [183] layer-based devices extended for most of the sensing organs of the human body [184] to detect colorless and odorless gasses [185] vibration-, respiration-, sound-and pulse-changes [186]. The analysis of biomarkers and stimuli occurs in a network of e-skin sensors.…”

Flexible Hybrid Sensor Systems with Feedback Functions

“…[ 49,306 ] Using such skin‐interfaced flexible displays seamlessly incorporated with multifunctional flexible sensor systems, measured information such as vital signs and surrounding stimuli could be instantaneously visualized on the display, without complex data acquisitions. This affords instant and intuitive feedback to users, enabling intriguing applications in the imaging of spatial pressure/tactile stimuli, [ 307–312 ] soft robots, [ 313,314 ] wearable healthcare technology, [ 315–319 ] human motion monitoring, [ 320 ] and security systems. [ 321,322 ] To achieve such skin‐mounted, smart, visualized sensor systems, various displays with high pixel resolution, high sensitivity, and superior deformability have been developed, such as inorganic/organic/polymer/quantum‐dot light‐emitting diodes (LEDs), or electroluminescent/electrochromic/thermochromic/mechanoluminescent displays.…”

Visco‐Poroelastic Electrochemiluminescence Skin with Piezo‐Ionic Effect

“…Local pressure applied to the resulting electronic-skin device could be spatially resolved and visually displayed on a pixel scale, which, as a consequence, could be quantified in terms of the local light intensity. This result motivated exploitation of pressure-sensitive device components (e.g., gate dielectrics, [12] integrated units, [13] and electrodes [14] ) within OLEDs. Fabrication of these devices necessitates integration of functional elements, including arrays of pressure sensors, display units, and driving units, which is a complicated task.…”