Direct and solvent-free patterning of flexible electrics through all-solid laser printing.

With the rapid development of stretchable and flexible electronic circuits, integrating patterned functional layers into flexible substrates through low-cost, high-efficiency methods has become crucial for advancing the electronics industry and is now a widely studied topic. However, traditional fabrication techniques for flexible electronics often encounter significant challenges-such as harsh processing conditions and residual solvents-that can degrade the electrical performance. Mask-free and solvent-free fabrication of patterned films remains a relatively new approach. All-solid laser printing (ASLP) is one such emerging technology, enabling the direct and precise transfer of charged solid powders onto a variety of flexible substrates through contactless electrostatic attraction. By utilizing direct melting and controlled recrystallization, ASLP produces high-quality thin films. This method easily achieves a range of patterned films, including composite functional films that maintain excellent luminescent properties. Furthermore, a high-performance transistor array-featuring both insulating and organic layers fabricated ASLP-has been successfully demonstrated. As a dry transfer printing technique, ASLP preserves the optical and electronic properties of materials, ensuring reliable device performance. With its simplicity, scalability, and design flexibility, ASLP presents a promising pathway for the efficient and large-scale fabrication of flexible optoelectronic devices.