Enabling Applied Process Control of Solution Deposition of Hydroxyapatite Using JMP® Software

Authors:<br/>Bríd Murphy^1,2and Michael A. Morris^1,2<br/>AMBER Research Centre, CRANN Institute, Trinity College Dublin, Dublin 2, Ireland<br/>School of Chemistry, Trinity College Dublin, Dublin 2, Ireland<br/>Abstract:<b> </b><br/>In any novel coating technique, there are various dependencies pertaining to process and coating outcome. This results in complex dependencies on a range of interacting variables which can be extremely challenging to understand. Achieving such an understanding for solution deposited hydroxyapatite would facilitate ramping up of a lab-based system to an industrial scale system with controlled repeatability.<br/>This work shows how automated computational models of raw data can be used to generate applied process controls for solution deposition of hydroxyapatite.<br/>JMP® statistical software is used to build a design of experiments with process parameters as factors and characterisation data as responses. The visualisation of this data through multivariate analysis and regression modelling shows links within and between factors and responses. The DOE yielded a model for the complex solution deposited HA process which is subsequently automated using JMP Scripting language.<br/>Some findings from the model include: (i) how initial substrate roughness influences oxygen atomic percentage of the films, (ii) how substrate roughness affects the proportionality between indicative spectroscopic peaks and (iii) how initial solution pH affects the weight of coating formed whereas temperature has little effect.<br/>An industrial scale system could use the findings of this model to apply control limits to processing parameters leading to repeatability of coatings across separate batches. Separately, findings of this model highlight links that would be scientifically significant and worth pursuing in further research.