def youngs_modulus_saenopy(youngs_modulus):
    """
    Defines the material properties for a linear-elastic hydrogel (such as Matrigel) hydrogel with a poission ratio of 0.25 (see [Steinwachs,2015], in this case Youngsmodulus equals K_0/6).
    
    Use None in saenopy
    
    Args:
        youngs_modulus(float) : Young's modulus of the material in Pascal for SAENO Simulation (see [Steinwachs,2015])
    """
    return {'K_0': youngs_modulus*6, 'D_0': None, 'L_S': None, 'D_S': None}