Abstract
In recent years, two-photon photopolymerization (2PP) has emerged as a preferred technique for microneedles (MNs) fabrication. Ormocomp, a class of ormocers (organically modified ceramics) is a photoresist that has been widely used in dental implants and is now preferred for MNs because of its excellent structural strength and biocompatibility. In this study, Ormocomp hollow microneedles (HMNs) were explored for their suitability for transdermal drug delivery. HMNs were designed and simulated for their structural strength during skin insertion. Velocity, flowrate and Reynold’s number in the HMNs connected to reservoir were also studied. Subsequently their fabrication was explored using 2PP. HMNs (3X3 array, 600µm height, 120µm outer diameter, 60µm inner diameter and 700 µm array spacing) were first fabricated on glass substrate and their fabrication and development step was optimised. Then in a novel process, a combination of direct laser writing technique for HMN base and 2 PP technique for HMN array was adopted. In this process, first a SU-8 base with through holes (100µm diameter, 3X3 array, 700µm array spacing) was fabricated using direct laser writing (DLW) process and then same dimension HMNs as fabricated earlier were aligned and fabricated on top of these through holes and fabricated using 2PP. The novelty of the work lies in obtaining the SU-8 base containing HMNs which was slowly separated from glass slide substrate with help of a blade.