{"title":"Mechanical finite element analysis of needle tip shape to develop insertable polymer-based microneedle without plastic deformation","authors":"Hiroaki Takehara , Mizuki Inada , Yukihiro Kanda , Takanori Ichiki","doi":"10.1016/j.jmbbm.2025.106885","DOIUrl":null,"url":null,"abstract":"<div><div>Bioabsorbable polymer microneedles are highly attractive as modernized medical devices for efficient yet safe transdermal drug delivery and biofluid biopsy. In this study, the elastoplastic deformation of polymer microneedles, having a high aspect ratio (over 5–10), is investigated using poly(lactic) acid polymer approved by the United States Food and Drug Administration to be generally considered safe. Microneedle geometries are comprehensively analyzed for tip geometries comprising the tip diameter (<em>ϕ</em><sub><em>t</em></sub>) and tip taper length (<em>l</em><sub><em>t</em></sub>) of 100 designs. Elastoplastic analysis is conducted using the finite element method to determine the typical geometries of the polymer microneedles to avoid elastoplastic deformation accompanied by fatal fracture based on the mechanical properties of the polymer materials. The design principles of microneedle geometries based on polymer material properties are important guidelines for developing polymer microneedles, overcoming their mechanical weakness, and ensuring excellent functions.</div></div>","PeriodicalId":380,"journal":{"name":"Journal of the Mechanical Behavior of Biomedical Materials","volume":"163 ","pages":"Article 106885"},"PeriodicalIF":3.3000,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Mechanical Behavior of Biomedical Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1751616125000013","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, BIOMEDICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Bioabsorbable polymer microneedles are highly attractive as modernized medical devices for efficient yet safe transdermal drug delivery and biofluid biopsy. In this study, the elastoplastic deformation of polymer microneedles, having a high aspect ratio (over 5–10), is investigated using poly(lactic) acid polymer approved by the United States Food and Drug Administration to be generally considered safe. Microneedle geometries are comprehensively analyzed for tip geometries comprising the tip diameter (ϕt) and tip taper length (lt) of 100 designs. Elastoplastic analysis is conducted using the finite element method to determine the typical geometries of the polymer microneedles to avoid elastoplastic deformation accompanied by fatal fracture based on the mechanical properties of the polymer materials. The design principles of microneedle geometries based on polymer material properties are important guidelines for developing polymer microneedles, overcoming their mechanical weakness, and ensuring excellent functions.
生物可吸收聚合物微针作为高效安全的经皮给药和生物液体活检的现代化医疗器械具有很高的吸引力。本研究采用经美国食品药品监督管理局(Food and Drug Administration)普遍认为安全的聚(乳酸)聚合物,研究高纵横比(大于5-10)聚合物微针的弹塑性变形。综合分析了微针的几何形状,包括100种设计的尖端直径(ϕt)和尖端锥度长度(lt)。基于高分子材料的力学性能,采用有限元法进行弹塑性分析,确定聚合物微针的典型几何形状,避免聚合物微针发生弹塑性变形并导致致命断裂。基于高分子材料特性的微针几何设计原则是开发聚合物微针、克服其机械缺陷、保证其优良功能的重要指导原则。
期刊介绍:
The Journal of the Mechanical Behavior of Biomedical Materials is concerned with the mechanical deformation, damage and failure under applied forces, of biological material (at the tissue, cellular and molecular levels) and of biomaterials, i.e. those materials which are designed to mimic or replace biological materials.
The primary focus of the journal is the synthesis of materials science, biology, and medical and dental science. Reports of fundamental scientific investigations are welcome, as are articles concerned with the practical application of materials in medical devices. Both experimental and theoretical work is of interest; theoretical papers will normally include comparison of predictions with experimental data, though we recognize that this may not always be appropriate. The journal also publishes technical notes concerned with emerging experimental or theoretical techniques, letters to the editor and, by invitation, review articles and papers describing existing techniques for the benefit of an interdisciplinary readership.