Self-propelling robotic capsules eliminate shaft looping of conventional colonoscopy, reducing patient discomfort. However, reliably moving within the slippery, viscoelastic environment of the colon remains a significant challenge. We present OSCAR, an ovipositor-inspired self-propelling capsule robot that translates the transport strategy of parasitic wasps into a propulsion mechanism for colonoscopy. OSCAR mechanically encodes the ovipositor-inspired motion pattern through a spring-loaded cam system that drives twelve circumferential sliders in a coordinated, phase-shifted sequence. By tuning the motion profile to maximize the retract phase relative to the advance phase, the capsule creates a controlled friction anisotropy at the interface that generates net forward thrust. We developed an analytical model incorporating a Kelvin-Voigt formulation to capture the viscoelastic stick--slip interactions between the sliders and the tissue, linking the asymmetry between advance and retract phase durations to mean thrust, and slider-reversal synchronization to thrust stability. Comprehensive force characterization experiments in ex-vivo porcine colon revealed a mean steady-state traction force of 0.85 N, closely matching the model. Furthermore, experiments confirmed that thrust generation is speed-independent and scales linearly with the phase asymmetry, in agreement with theoretical predictions, underscoring the capsule's predictable performance and scalability. In locomotion validation experiments, OSCAR demonstrated robust performance, achieving an average speed of 3.08 mm/s, a velocity sufficient to match the cecal intubation times of conventional colonoscopy. By coupling phase-encoded friction anisotropy with a predictive model, OSCAR delivers controllable thrust generation at low normal loads, enabling safer and more robust self-propelling locomotion for robotic capsule colonoscopy.

翻译：自推进机器人胶囊消除了传统结肠镜检查中的轴环问题，减轻了患者不适。然而，在结肠光滑、粘弹性的环境中可靠移动仍是一个重大挑战。本文提出OSCAR，一种受产卵器启发的自推进胶囊机器人，它将寄生蜂的输送策略转化为结肠镜检查的推进机制。OSCAR通过弹簧加载的凸轮系统机械编码受产卵器启发的运动模式，该系统以协调的相移序列驱动十二个周向滑块。通过调整运动曲线以最大化回缩阶段相对于前进阶段的持续时间，胶囊在界面处产生受控的摩擦各向异性，从而产生净前向推力。我们建立了一个结合Kelvin-Voigt公式的解析模型，以捕捉滑块与组织之间的粘弹性粘滑相互作用，将前进与回缩阶段持续时间的不对称性与平均推力联系起来，并将滑块反转同步性与推力稳定性相关联。在离体猪结肠中进行的全面力表征实验显示，平均稳态牵引力为0.85 N，与模型预测高度吻合。此外，实验证实推力生成与速度无关，并随相位不对称性线性缩放，这与理论预测一致，突显了胶囊性能的可预测性和可扩展性。在运动验证实验中，OSCAR表现出稳健的性能，平均速度达到3.08 mm/s，该速度足以匹配传统结肠镜的盲肠插管时间。通过将相位编码的摩擦各向异性与预测模型相结合，OSCAR在低法向载荷下实现了可控的推力生成，为机器人胶囊结肠镜检查提供了更安全、更稳健的自推进运动能力。