Fig. 2: Design model for converters and metamaterials.
From: Non-reciprocal and non-Newtonian mechanical metamaterials
a The simple principle of rotation and torque is induced by a unidirectional force F applied on a non-centrosymmetric object. b The design of the converter uses off-axis loading of tilted cantilevers with a concentrated mass at the end. The arms are deflected and clipping of the mass is expected on the side wall. The response is exalted at the resonance frequency of the ball-beam system (mass-spring). v: the velocity of beam lateral vibration. c A planar example (2D) of a non-reciprocal and non-Newtonian unit cell is shown. d An example of a 3D unit cell inspired by the previous 2D unit cell is depicted. e, f Micro-scale 2D planar unit cell and 3D metamaterial fabricated by two-photon lithography 3D direct laser writing. The geometry parameters for 2D unit cell and 3D metamaterial are t1 = 4 μm, t2 = 10 μm, t3 = 15 μm, t4 = 30 μm, t5 = 50 μm, r = 20 μm, d = 20 μm, l = 130 μm, l1 = 126 μm, l2 = 70 μm, l3 = 25 μm, l4 = 130 μm, l5 = 400 μm, and θ = 45°. g Numerical simulation of the amplitude of the force on the 2D unit cell for sources 1 and 2 and as a function of frequency. h The experimental setup is described in the “Methods” section. i The displacements in the x- and y-directions of the free end (point A) of the tilted cantilever beam are plotted for different frequencies and loading directions.
