Simulation, analysis and characterization of solid microneedles for biomedical applications

Abstract

The uniformly smooth and sharp microneedles have great significance in contact spectroscopy, 3D printing, biomedical and nanotechnology. The stability, bio-stability, conductivity and mechanical properties of the gold (Au) make it effective rather than the other metals such as tungsten, copper, platinum and graphite. The surface quality, proper dimension such as the tip, cone angle is the matter of the trial and practice matter. It was the main issue to develop a controlled optimized methodology to obtain the gold needles of specific dimensions in regular and systematic way. The Ansys simulation of solid microneedle has been done to check on what stress the deflection occurs on microneedles. Then fuzzy optimization has performed to optimize the parameter of the etching set up such as the voltage, current and time of etching as an input parameter and the tip size and the conical section length as the output parameters. After the simulation and optimization the experiment of the etching has performed with the 3M solution of NaCl in deionized water and small amount of hydropercaloric acid. The fabricated needles have been then characterized by Scanning electron microscopy (SEM) to observe the morphology and the dimensions. The fuzzy analysis has been performed for optimization of the inputs voltage of range 1–10volt, current of range 1–100 mA and etching times from 1–15minutes. These optimized values are calculated by the fuzzy analysis such as the voltage is 58.6 mA, etching time 15 minutes and the voltages found to be 10 volt. Fuzzy analysis gives the simulated size of the tip 10.6μm and Mamdani models gives the 10.7μm which have the 0.01% error and the cone length for the Mamdani was found to be 500μm and the simulated values 497 having the 0.03% error which have very close approximation with the experimental values from the SEM micrographs that which also gives the values of the cone length from 400–500μm and the tip size from 10-20μm for the time 10-15minute whose values was optimized by the fuzzy analysis.