Hand-Printed Paper-Based Devices: Toward Green Flexible Electronics and Sensing Applications

The rapid advancement of modern electronics has led to a surge in solid electronic waste, posing significant environmental and health challenges. This review focuses on recent developments in paper-based electronic devices fabricated through low-cost, hand-printing techniques, with particular emphasis on their application in energy harvesting, storage, and sensing. Unlike conventional plastic-based substrates, cellulose paper offers several eco-friendly advantages, including biodegradability, recyclability, and low fabrication cost. By integrating functional nanomaterials such as 2D chalcogenides, metal oxides, conductive polymers, and carbon-based structures onto paper, researchers have achieved high-performance devices such as broadband photodetectors (responsivity up to 52 mA/W), supercapacitors (energy density ~15.1 mWh/cm²), and pressure sensors (sensitivity ~18.42 kPa⁻¹). The hand-printing approach, which eliminates the need for sophisticated equipment and toxic solvents, provides a promising route for scalable, sustainable, and disposable electronics. This review not only outlines fabrication methods and key performance metrics but also discusses current challenges and future directions for realizing robust, flexible devices aligned with green technology and the UN’s Sustainable Development Goals.