Determination of the mechanical properties of polymeric microneedles by micromanipulation  

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Colleges, School and Institutes

External organisations

  • Sichuan University


Precise characterization of the mechanical properties of polymeric microneedles is crucial for their successful penetration into skin and delivery of the loaded active ingredients. However, most available strategies for this purpose are based on compression of the whole patch, which only provide the average rupture force of the needles and can not give information on the variations across individual microneedles in the patch. In this study, we determined the mechanical strength of individual microneedles of two types of hyaluronic acid microneedles with or without loaded model drugs using a micromanipulation technique. The applied force as a function of displacement of the microneedles was recorded, which was used to determine the rupture displacement, rupture force, and then to derive and calculate normal stress-deformation curve, rupture stress and Young′s modulus of individual microneedles. The obtained data suggest that the molecular weight of the polymer and the loading of drug into the microneedles can significantly affect the rupture behavior and mechanical properties of the microneedles, which provides a foundation for preparing sufficiently strong microneedles for controlled drug delivery.

Bibliographic note

Funding Information: We acknowledge the financial support of the National Natural Science Foundation of China (No. 81961130395 ), China Postdoctoral Science Foundation Grant ( 2019M663534 ), Program of Introducing Talents of Discipline to Universities (Plan 111, No. B18035 ), and NAF\R1\191217 - Newton Advanced Fellowships 2019. Publisher Copyright: © 2021 Elsevier Ltd


Original languageEnglish
Article number104384
Number of pages7
JournalJournal of the Mechanical Behavior of Biomedical Materials
Early online date10 Feb 2021
Publication statusPublished - May 2021


  • Mechanical properties, Micromanipulation, Normal stress, Polymeric microneedles, Rupture force