Effects of pore shape and porosity on the properties of porous LNKN ceramics as bone substitute

A porous lead-free piezoelectric ceramic is investigated as direct bone substitute. Porous lithium sodium potassium niobate (Li0.06Na0.5K0.44)NbO3 specimens were prepared by pore-forming method. Different volume fraction of ammonium oxalate monohydrate and poly(methyl methacrylate) were used as porogens to obtain different pore shape and porosity. Scanning electron microscopy showed a bicontinuous 3–3 structure of interconnected pores 150–250 μm in size. The piezoelectric constants and electromechanical coupling coefficients may be controlled by both size and shape of the porogens to tune for the best biological response. Such materials show promise for use as a piezoelectric composite bone substitute.