interfacial friction control; architected materials; mechanical metamaterials; kirigami; friction
Rafsanjani Ahmad, Jin Lishuai, Deng Bolei, Bertoldi Katia (2019), Propagation of pop ups in kirigami shells, in Proceedings of the National Academy of Sciences
Rafsanjani Ahmad, Zhang Yuerou, Bangyuan Liu, Rubinstein Shmuel, Bertoldi Katia (2018), Kirigami skins make a simple soft actuator crawl, in Science Robotics
, 3(15), eaar7555.
Shang Xiao, Liu Lu, Rafsanjani Ahmad, Pasini Damiano (2018), Durable bistable auxetics made of rigid solids, in Journal of Materials Research
, 33(3), 300-308.
Rafsanjani Ahmad, Bertoldi Katia (2017), Buckling-Induced Kirigami, in Physical Review Letters
, 118(8), 084301.
Rafsanjani Ahmad, Pasini Damiano (2016), Bistable auxetic mechanical metamaterials inspired by ancient geometric motifs, in Extreme Mechanics Letters
, 9, 291-296.
Friction forces resist the relative motion between two sliding surfaces and are present everywhere in our daily activities such as walking, driving a car, writing on paper, playing a cello and so on. Estimates show that in industrialized countries about 5% of the gross domestic product (GDP) is lost through friction. For instance, one-third of car fuel consumption is due to friction loss. Thus, control and manipulation of frictional forces is extremely important for a variety of applications, which can save energy and billions of Swiss francs. From a material science perspective, the frictional forces between two sliding surfaces depend on the interactions at the interface (e.g. electrostatic, hydrophobic, adhesion, etc.) and are strongly affected by its morphology. In this project, I will utilize a combination of experiments and simulations to design a class of structural surfaces that are able to control frictional properties. The core idea is to transform the passive state of friction to an active controllable state by harnessing kirigami principles, the Japanese art of cutting paper. The main advantage of kirigami meta-surfaces is that their morphology can be reversibly and actively controlled by exploiting mechanical induced elastic instabilities, providing a novel and robust approach to tune and control friction. An enormous variety of kirigami patterns exist, which enables us to design various frictional surfaces with, desired properties and functionalities.