Biomedical Sensing with Hydroxyapatite Ceramics in GHz Frequency Range

Abstract

A.Al-Shamma'a@ljmu.ac.uk, e Tofail.Syed@ul.ie Keywords: Hydroxyapatite, GHz frequency range, biocompatible sensor, real-time pressure sensing in medical applications, piezoelectic and pyroelectric properties, powder and films.Abstract. Hydroxyapatite (HA) is a leading biocompatible material extensively used for bone implants as a porous ceramic graft and as a bioactive coating. Electrical characteristics of HA can be employed in implantable devices for real-time in vivo pressure sensor applications such as in knee or hip prosthesis. In particular, high piezo and pyroelectricity of HA, its polarisation by electron beam and selective adsorption of proteins on polarised domains indicate the potential for real-time biosensing applications of HA. For this purpose, a comprehensive understanding of the dielectric behaviour of different forms of HA over a frequency range relevant for biomedical sensing is critical. Such information for HA, especially its frequency dependent dielectric behaviour over the GHz range, is rare. To this end, we report on novel investigations of properties of HA in powder and film forms in the GHz frequency range.

Detection of adsorbed cytochrome c on hydroxyapatite thick films using a microwave sensor

“…In addition no cracks or other defects were found. Dielectric properties of HA and its response in the GHz frequency range has been previously analyzed using a microwave cavity [19]. Figure 2 illustrates the spectra recorded for HA and air using and IDE microwave sensor in the 0.01-15 GHz frequency region.…”

“…Dielectric properties of HA powders and thick films have been previously demonstrated using a microwave cavity [19]. Cytochrome c is a well characterized heme protein with large patches of positive charge [20] that can facilitate interaction with negatively charged surfaces such as those obtained on HA.…”

Enhanced high-temperature electrical response of hydroxyapatite upon grain size refinement

“…[3,4] Different strategies like microstructural engineering [5] and single valence ion doping [6] were applied to enhance conductivity of hydroxyapatite.…”

Inert atmosphere processing of hydroxyapatite in the presence of lithium iron phosphate

“…Materials based on hydroxyapatite (HAp) ceramics are widely studied as components for medical applications, sensors, magnetic separations, catalyst support, etc [1][2][3][4]. Different engineering and scientific approaches, like microstructural optimization [5][6][7][8] and addition of different additives [9,10], were implemented for enhancement of functional response.…”