Advances in robotics and micromechanical systems demand miniaturized, low-cost electromechanical sensors. Conventional micro-electromechanical systems (MEMS) rely on complex, expensive top-down fabrication, limiting scalability. Here, we introduce a bottom-up approach for fabricating a flexible acceleration sensor using cellulose nanocrystal (CNC) films combined with conductive 2D MXene nanosheets. The self-assembled hybrid film exhibits sensitivity to acceleration, enabling precise three-axis motion detection. Functioning like a flexible field-effect transistor, the device uses acceleration-induced film deformation to generate charge separation in the chiral piezo films, producing a gating effect with measurable voltage shifts proportional to applied acceleration. This piezoelectric response allows real-time accurate motion tracking. Unlike conventional sensors, the device exhibits nonlinear behavior and is insensitive to the motion direction. Our approach offers a cost-effective solution for applications requiring dynamic motion detection and precise acceleration quantification, while simplifying fabrication and expanding the possibilities for next-generation nano and micro sensing technologies.