Gupta Rahul Kumar, Kant Raushan, Soni Harsh, Sood A K, Ramaswamy Sriram
Tata Institute of Fundamental Research, Gopanpally, Hyderabad 500 107, India.
Department of Physics, Indian Institute of Science, Bangalore 560 012, India.
Phys Rev E. 2022 Jun;105(6-1):064602. doi: 10.1103/PhysRevE.105.064602.
We show from experiments and simulations on vibration-activated granular matter that self-propelled polar rods in an elastic medium on a substrate turn and move towards each other. We account for this effective attraction through a coarse-grained theory of a motile particle as a moving point-force density that creates elastic strains in the medium that reorient other particles. Our measurements confirm qualitatively the predicted features of the distortions created by the rods, including the |x|^{-1/2} tail of the trailing displacement field and nonreciprocal sensing and pursuit. A discrepancy between the magnitudes of displacements along and transverse to the direction of motion remains. Our theory should be of relevance to the interaction of motile cells in the extracellular matrix or in a supported layer of gel or tissue.
我们通过对振动激活的颗粒物质进行实验和模拟表明，在基底上弹性介质中的自驱动极性杆会转向并相互靠近。我们通过将运动粒子视为移动点力密度的粗粒化理论来解释这种有效吸引力，该移动点力密度在介质中产生弹性应变，从而使其他粒子重新定向。我们的测量定性地证实了由杆产生的畸变的预测特征，包括尾随位移场的|x|^{-1/2}尾部以及非互易传感和追踪。沿运动方向和垂直于运动方向的位移大小之间仍存在差异。我们的理论应该与细胞外基质中或凝胶或组织支撑层中的运动细胞的相互作用相关。
