This study presents the development of Ag₂Se-based thermoelectric films and flexible devices using inkjet printing technology. The researchers synthesized Ag₂Se nanoparticles and formulated them into printable inks. By optimizing the ink formulation and printing parameters, they achieved high-resolution pattern arrays with microscale resolution. The printed Ag₂Se films exhibited a (00 l)-textured feature and an exceptional power factor of 1097 μWm⁻²K⁻² at 377 K. The high-resolution device integration allowed for the fabrication of fully inkjet-printed flexible devices with a record-high normalized power of 2 μWK⁻²cm⁻² and superior flexibility. The devices demonstrated the ability to generate power from environmental and human body heat, offering potential applications in portable/wearable electronics and low-power IoT devices. The study highlights the potential of inkjet printing to revolutionize the design and manufacturing of flexible thermoelectric devices, reducing costs and enabling their integration into emerging electronic systems.This study presents the development of Ag₂Se-based thermoelectric films and flexible devices using inkjet printing technology. The researchers synthesized Ag₂Se nanoparticles and formulated them into printable inks. By optimizing the ink formulation and printing parameters, they achieved high-resolution pattern arrays with microscale resolution. The printed Ag₂Se films exhibited a (00 l)-textured feature and an exceptional power factor of 1097 μWm⁻²K⁻² at 377 K. The high-resolution device integration allowed for the fabrication of fully inkjet-printed flexible devices with a record-high normalized power of 2 μWK⁻²cm⁻² and superior flexibility. The devices demonstrated the ability to generate power from environmental and human body heat, offering potential applications in portable/wearable electronics and low-power IoT devices. The study highlights the potential of inkjet printing to revolutionize the design and manufacturing of flexible thermoelectric devices, reducing costs and enabling their integration into emerging electronic systems.