PiezoMaterials

=Evidence of Osteogenesis via Piezoelectric Materials=

Seminal Work
Early evidence of the piezoelectric effect of bone was discovered by Fukada. = =

Progressive Theories
Further studies by Marino led to theories of stress-generated surface potentials. In the late 1970s, it was established that sustained electrical potential led to bone growth and resorption. The math for long wave propagation in bone was modeled in 1990.

Newhman established notations for composite piezoelectrics. A 3-3 composite occupies 3D space. It was found by Rittenmeyer et. al that a softer polymer phase in a 3-3 piezoelectric offered higher d_33. Somehow the softer phase transfers stress to the ceramic phase. This mechanism is possibly a similar mechanism for the piezo effect in bone. __An interesting experiment would be to test the d_33 of decolligenated bone to regular bone and observe the shift__. Some approximate values for commen piezoelectric materials are listed in the table below.
 * ~ Material ||~ d_33 (pC/N) ||
 * BaTiO3 ||= 190 ||
 * PZT-8 ||= ~225 ||
 * NKN ||= 60 ||
 * bone ||= ~8 ||

=Basic Science Experiments=

Attraction of amino acids quartz surfaces
More recent experiments by Hench observe self alignment of polyanaline on charged SiO2 surfaces. Analine is the simplest and most common amino acid in all life forms. Absorbing N2 gas on SiO2 eliminated bioactivity. A component of the Bioactive Substrate theory is the acculation of catalblic and anabolic molecules on charged bioactive surfaces that led to forming the first L-nuleic and D+ base sugars key to all life forms.

Surface charge on Bioactive Surfaces
Protein adsorption kinetics on bioactive substrates suggests surface charge is an important factor. = =