Laser-Architected Shape-Configurable Vertical Graphene Thermoacoustic Loudspeakers for 3D Acoustic Emission

Recent advances in thermoacoustic (TA) loudspeakers have focused on freeform, conformal audio systems that enable conformal integration, spatial sound control, and seamless transformation between 2D and 3D geometries. However, their practical use remains limited by low sound pressure levels (SPLs) and poor mechanical adaptability, primarily due to insufficient thermal dissipation and structural rigidity. Here, we report a high-performance, shape-configurable TA loudspeaker based on vertically aligned reduced graphene oxide (VrGO), fabricated through a dual-laser process combining continuous-wave (CW) CO₂ laser reduction with pulsed laser patterning. The CW laser induces vertical microstructuring and graphitization, enhancing thermal transport and reducing the heat capacity per unit area, while the pulsed laser enables precise patterning into complex geometries such as kirigami and 3D prismoids. The VrGO loudspeakers exhibit superior SPL (85 dB at 10 kHz), excellent heat dissipation, and high resilience, maintaining over 75% SPL under 500% strain and stable output over 1000 cycles. The patterned VrGO structures enable omnidirectional emission, conformal attachment, and 2D-3D transformation. Notably, even thick VrGO films retain strong acoustic performance, outperforming conventional TA devices. This scalable, material-efficient strategy offers tunable directivity, adaptability, and multifunctionality for next-generation wearable audio devices, interactive electronics, and conformal human-machine interfaces.