High-Performance, Computer-Controlled Bipedal DNA Motor
Achieving precise, repeatable motion at the molecular scale remains a central challenge in the development of synthetic molecular machines. Here we report a high-fidelity, fast bipedal DNA walker that moves bidirectionally along a DNA origami track using a fuel-before-antifuel operational scheme that suppresses trap states typical of externally powered DNA motors. Automated, computer-controlled microfluidics enables programmable trajectory execution with >98% yield per step and sustained bidirectional walking over distances of up to 360 nm, as monitored by single-molecule FRET. Kinetic analysis reveals rapid leg lifting but slower leg placement due to inhibitory fuel-antifuel heterocomplex formation, identifying a mechanistic bottleneck that can be mitigated through optimization of fuel, antifuel and foothold design. The resulting motor operates with efficiencies of up to 4 orders of magnitude higher than previous externally controlled DNA walkers, establishing a robust framework for deterministic, programmable molecular transport.