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The integumentary system in animals serves as an important line of defence against physiological and mechanical external forces. Over time, integuments have evolved layered structures (scales, cuticle and skin) with high toughness and strength to resist damage and prevent wound expansion. While previous studies have examined their defensive performance under low-rate conditions, the failure response and damage resistance of these thin layers under dynamic biological puncture remain underexplored. Here, we utilize a novel experimental framework to investigate the mechanics of dynamic puncture in both bilayer structures of synthetic tissue-mimicking composite materials and natural skin tissues. Our findings reveal the remarkable efficiency of a thin outer skin layer in reducing the overall extent of dynamic puncture damage. This enhanced damage resistance is governed by interlayer properties through puncture energetics and diminishes in strength at higher puncture rates due to rate-dependent effects in silicone tissue simulants. In addition, natural skin tissues exhibit unique material properties and failure behaviours, leading to superior damage reduction capability compared with synthetic counterparts. These findings contribute to a deeper understanding of the inherent biomechanical complexity of biological puncture systems with layered composite material structures. They lay the groundwork for future comparative studies and bio-inspired applications.
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This content will become publicly available on December 15, 2025
Permeation of per- and polyfluoroalkyl substances (PFAS)-laden leachate in landfills as an outcome of puncture failures of high-density polyethylene geomembranes
In response to growing environmental concerns regarding the presence of per- and polyfluoroalkyl substances (PFAS) in landfills, this study explores PFAS permeation through pinhole defects of high-density polyethylene (HDPE) geomembranes (GMs) experimentally. Specifically, this study aims to: (i) investigate the adsorption of PFAS onto HDPE GMs, (ii) evaluate the effectiveness of GMs experimentally in retaining PFAS-laden leachate in the event of a puncture failure, (iii) assess the critical conditions leading to puncture failure of GM using mechanical characterization testing with complementary finite element method (FEM) analyses with the input data from mechanical characterization. Our findings show limited intermolecular attractive interactions between PFAS and GMs, and surfactant properties of PFAS contribute to higher leachate permeation through pinholes. In general, highly fluorinated, short chain PFAS exhibit increased permeation rates, which was attributed to their size and greater propensity to align at the water-air interface. This study underlines the environmental implications of PFAS-laden leachates especially when there are no proper liner systems or leachate collection systems in place underscoring the necessity for modern landfill design and management practices to mitigate environmental risks associated with PFAS.
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- Award ID(s):
- 2219832
- PAR ID:
- 10557831
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Environmental Pollution
- Volume:
- 363
- Issue:
- P2
- ISSN:
- 0269-7491
- Page Range / eLocation ID:
- 125234
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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