An elastic device providing means of controlling its stiffness by controlling the tension of the string or group of springs resulting in adjustable transverse stiffness of it, arranged in matrix to enable the control of spatial stiffness of a 2D matrix in unlimited resolution.

An adjustable mattress frame comprises a central body segment and upper and lower body adjustable segments pivotally connected by a hinge to said central body segment, said central body segment being provided with two actuation modules suitable to actuate said upper and lower body segments respectively.

An adjustable mattress frame comprises a central body segment and upper and lower body adjustable segments pivotally connected by a hinge to said central body segment, said central body segment being provided with two actuation modules suitable to actuate said upper and lower body segments respectively.

An elastic device providing means of controlling its stiffness by controlling the tension of the string or group of springs resulting in adjustable transverse stiffness of it, arranged in matrix to enable the control of spatial stiffness of a 2D matrix in unlimited resolution.