Multi-scale micro-projection based stereolithography for microneedle fabrication: process development and optimization

Stereolithography (SLA), one type of 3D printing, has been receiving increasing attention with the development of related technologies. It is now one a promising method for the construction of high-precision bio-medical-related objects due to its high resolution compared to other processes. However, SLA is still suffering from making tradeoffs between resolution and overall printing size when micro-features are desired over a large part. In this thesis, I present the design of a multi-scale micro-projection stereolithography system that is capable of fabricating objects with features of micro, meso, and macro size. Microneedle arrays are constructed as drug delivery devices with the system using designed PEGDA-based biocompatible materials with loading of Naltrexone – a drug helps prevent relapses into alcohol and drug abuse. It provides increased geometric freedom for designs and makes many potential applications accessible. Meanwhile, a framework for optimizing fabrication accuracy is purposed integrating deep learning techniques to further increase the accuracy of micro-stereolithography, which is effective and easy to apply to other systems. This study provides an ultra-precision 3D printing method that can be applied to microneedles and other applications in tissue engineering.