Experimental study of capillary aggregation Arshad A Kudrolli, Department of Physics, Clark University, Worcester, MA 01610 Using the apparatus build which is shown on the left, aggregation properties of cohesive granular spheres were studied in detail with a model two dimensional system of particles floating at the air-liquid interface. The meniscus formed around the floating spheres results in cohesive forces. We find that the forces between cohesive particles add linearly over a wide range of distances but fails where particles are closer than their diameter. Further, lubrication forces and torque due to the non-linear nature of attraction lead to tunable structures. Post-doctoral researcher Michael Berhanu, and undergraduate students Darija Cosic, Fouad Abdul Ameer, and visiting student Marie-Julie Dalbe were supported and contributed to the work reported.