Active colloidal assembly has advanced the construction of patchy architectures and stimuli-responsive microsystems—yet structural diversity remains intrinsically limited by field-aligned polarization—that predominantly yield colloidal chains or aligned clusters. Here, we exploit curved liquid interfaces as geometric guidance to overcome orientation constraints via gravity–electric field interplay. The tilted interface amplified subcritical gradient electric forces $(\sim {10}^{-4} \mathrm{nN})$ against gravitational sedimentation and Brownian noise, enabling even low-density colloidal systems (2.5 wt %) to exhibit a buckling effect that generates counterintuitive assemblies. These processes are mechanistically distinct from well-known evaporation-induced buckling. Crucially, dielectrophoretic self-regulation under electric field confers frequency (10 kHz–1 MHz) and strength-independent buckling behaviors, enabling robust programmable architectures during colloidal spatial repositioning. These findings elucidate a principle where competing nonuniform and uniform fields enable expanding accessible configurations in orientation-agnostic assembly. This framework is generalizable to multimodal physical fields (magnetic, optical, and acoustic), providing promise for reconfigurable optical devices and the programmable patchy capsules.

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• Electrophoresis
• Patterns in complex systems
• Actuating materials
• Nanoclusters
• Crystal phenomena