Adhesion between microgripper end-effector and a nano/micro-object is a main topic for manipulation in micro- and nanoscale. Tuning this force is a great challenge. Adhesion force is directly 2 linked to the chemical composition and the surface roughness of both, the object and the gripper. Recently, we proposed a multispheres Van der Waals force model able to predict this force. The surface used was structured by an array of polystyrene spheres with radii from 35 nm to 2 mm. The experimental pull-off forces have confirmed our model. In this present work, we analyzed other innovating structure such as non-closed packed polystyrene (PS) spheres and organized Si Nanostructures, formed by chemical etching. The adhesion values of the pull-off force measured on these structures were very low (in the range of 2 to 10 nN), and suggest that these new structures have non-adhesive properties. A new model taking in account the roughness and the organization of the PS spheres and Si Nanostructures has been developed to predict these new properties.