Wireless, 3D Optical Sensor Fabricated Using Mechanical Buckling for Navigation and Agriculture Applications

Abstract Flexible optoelectronics have broad applications in healthcare and various industries. Unlike traditional (two‐dimensional) 2D designs, flexible 3D optical sensors enable advanced functions like light directionality detection, intensity mapping, and velocity measurement. However, their integration with 2D circuit boards adds manufacturing complexity. Solving this could unlock untapped applications in navigation, agriculture, and remote sensing. In this study, selective buckling of flexible circuit boards is investigated to develop an all‐in‐one flexible (three‐dimensional) 3D optical sensor for light detection with high sensitivity to periodic light pulses. By employing a buckling‐based design, the developed flexible 3D phototransistor is found to be adjustable for measuring incident light angles between 0° and 87°, with an average error of less than 5°. Additionally, the sensor is able to measure object velocity with a maximum deviation of only 1.5% from the actual speed. In this design, the flexible circuit board is also integrated with Bluetooth Low Energy (BLE) technology to wirelessly transmit readings to a smartphone application to enable efficient data processing, transmission, visualization, and analysis. The platform's effectiveness is then demonstrated for unmanned aeraial vehicles (UAV) navigation and solar tracking, highlighting its strong potential for real‐world use in autonomous systems and environmental monitoring.