Dynamically Tunable Friction via Subsurface Stiffness Modulation. - Siavash Sharifi; Caleb Rux; Nathaniel Sparling; Guangchao Wan; Amir Mohammadi Nasab; Arpith Siddaiah; Pradeep L. Menezes; Teng Zhang; Wanliang Shan (Frontiers Robotics AI, 2021)