  This paper reviews recent literature results on the mechanics of structures
formed by layers of pentamode lattices alternating with stiffening plates,
which can be effectively employed for the development of seismic isolation
devices and vibration attenuation tools, with nearly complete band gaps for
shear waves. It is shown that such structures, named pentamode bearings, can
respond either in the stretching-dominated regime, or in the bending-dominated
regime, depending on the nature of the joints connecting the different members.
Their response is characterized by high vertical stiffness and theoretically
zero shear stiffness in the stretching dominated regime, or considerably low
values of such a quantity in the bending dominated regime. Available results on
the experimental response of 3d printed models to combined compression and
shear loading highlight that the examined structures are able to exhibit energy
dissipation capacity and effective damping that are suitable for seismic
isolation devices. Their fabrication does not necessarily require heavy
industry, and expensive materials, being possible with ordinary 3-D printers.
