Fully-Printed Optical-Electric Dual Mode Flexible Sensor

As a pivotal component of smart home control systems (SHCS), the human-computer interaction (HCI) interface facilitates human-home information exchange and control. But contemporary HCI interfaces still harbor substantial security vulnerabilities due to the static and singular nature of the collected information. In this study, we formulate high-performance ZnS:Mn²⁺ mechanoluminescence (ML) ink featuring high-resolution printing capability (around 100 µm) and achieve a stress detection threshold as low as 0.01 MPa. Subsequently, we present an optical-electric dual-mode flexible sensor (OEDM-FS) crafted combining 2D and 3D printing technologies. This sensor integrates a capacitive pressure sensor (CPS) with a ML sensor. It precisely responds to the magnitude and distribution of applied stress through capacitive output and luminescent imaging. The system boasts exceptional stability in stress sensing (signal fluctuation below ±0.3% under fatigue testing involving over 10 000 cycles), and it can achieve a very high-resolution stress spatial distribution up to about 200 micrometers. By amalgamating the ML signals with machine learning algorithms, we can accurately identify stress distribution with distinct characteristics, attaining an impressive accuracy rate of 98.5%. Furthermore, we demonstrate the functionality of this OEDM-FS as an HCI interface for human recognition and its potential applications within SHCS.