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An Integrated Approach to Control the Penetration Depth of 3D-Printed Hollow Microneedles

Authors :
Kendall Marie Defelippi
Allyson Yuuka Saumei Kwong
Julia Rose Appleget
Rana Altay
Maya Bree Matheny
Mary Margaret Dubus
Lily Marie Eribes
Maryam Mobed-Miremadi
Source :
Applied Mechanics, Vol 5, Iss 2, Pp 233-259 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

A variety of hollow microneedle (HMN) designs has emerged for minimally invasive therapies and monitoring systems. In this study, a design change limiting the indentation depth of the (3D) printed custom microneedle assembly (circular array of five conical frusta with and without a stopper, aspect ratio = 1.875) fabricated using stereolithography has been experimentally validated and modeled in silico. The micro-indentation profiles generated in confined compression on 1 mm ± 0.073 mm alginate films enabled the generation of a Prony series, where displacement ranged from 100 to 250 µm. These constants were used as intrinsic properties simulating experimental ramp/release profiles. Puncture occurred on two distinct hydrogel formulations at the design depth of 150 µm and indentation rate of 0.1 mm/s characterized by a peak force of 3.5 N (H = 31 kPa) and 8.3 N (H = 36.5 kPa), respectively. Experimental and theoretical alignments for peak force trends were obtained when the printing resolution was simulated. Higher puncture force and uniformity inferred by the stopper was confirmed via microscopy and profilometry. Meanwhile, poroviscoelasticity characterization is required to distinguish mass loss vs. redistribution post-indentation through pycnometry. Results from this paper highlight the feasibility of insertion-depth control within the epidermis thickness for the first time in solid HMN literature.

Details

Language :
English
ISSN :
26733161
Volume :
5
Issue :
2
Database :
Directory of Open Access Journals
Journal :
Applied Mechanics
Publication Type :
Academic Journal
Accession number :
edsdoj.672bb8efd0e404bb59b951d609b5666
Document Type :
article
Full Text :
https://doi.org/10.3390/applmech5020015