A three-dimensional polymer scaffolding material exhibiting a zero Poisson's ratio

Abstract

Poisson’s ratio describes the degree to which a material contracts (expands) transversally when axially strained. A material with a zero Poisson’s ratio does not transversally deform in response to an axial strain (stretching). In tissue engineering applications, scaffolding having a zero Poisson’s ratio (ZPR) may be more suitable for emulating the behavior of native tissues and accommodating and transmitting forces to the host tissue site during wound healing (or tissue regrowth). For example, scaffolding with a zero Poisson’s ratio may be beneficial in the engineering of cartilage, ligament, corneal, and brain tissues, which are known to possess Poisson’s ratios of nearly zero. Here, we report a 3D biomaterial constructed from polyethylene glycol (PEG) exhibiting in-plane Poisson’s ratios of zero for large values of axial strain. We use digital micro-mirror device projection printing (DMD-PP) to create single- and double-layer scaffolds composed of semi re-entrant pores whose arrangement and deformation mechanisms contribute the zero Poisson’s ratio. Strain experiments prove the zero Poisson’s behavior of the scaffolds and that the addition of layers does not change the Poisson’s ratio. Human mesenchymal stem cells (hMSCs) cultured on biomaterials with zero Poisson’s ratio demonstrate the feasibility of utilizing these novel materials for biological applications which require little to no transverse deformations resulting from axial strains. Techniques used in this work allow Poisson’s ratio to be both scale-independent and independent of the choice of strut material for strains in the elastic regime, and therefore ZPR behavior can be imparted to a variety of photocurable biomaterial.

Cancer cell migration within 3D layer-by-layer microfabricated photocrosslinked PEG scaffolds with tunable stiffness

“…PEG-based biomaterials have been used extensively for tissue engineering of bone, vasculature and other tissues because of their high water content, biocompatibility and tunable mechanical properties [31, 32]. Previously, we have used the DMD-PP method to create 3D PEG-based biological scaffolds with complex internal architectures at microscale resolutions [33–38]. PEG-based optically transparent 3D scaffolds, are also compatible with standard microscopy techniques and there are minimal variations among scaffolds using the DMD-PP method.…”

Maximum Poisson's Ratios in Planar Isotropic Crystals of Binary Hard Discs at High Pressures

“…www.advancedsciencenews.com www.pss-b.com hand, Poisson's ratios of systems S3, S3i, and S6i in the close packing limit tend to some intermediate values between hard discs, for which v is equal to 0.1308 (22) [45] and the maximum value (þ1) allowed for isotropic 2D systems. For both models, S3 and S3i the Poisson's ratio at close packing is equal to 0.722(4) while for S6i structure it tends to 0.243 (8).…”

“…[1] From conditions of mechanical stability it follows that, in the case of elastic isotropic media, the Poisson's ratio may take values in the range À1 < ν < 1= D À 1 ð Þwhere D is the dimension of the system. [2] In recent years, systems [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and theoretical models [18][19][20][21][22][23][24][25][26][27][28][29][30] with various Poisson's ratios were intensively studied.…”

A composite material with Poisson’s ratio tunable from positive to negative values: an experimental and numerical study

“…Most traditional materials have a positive Poisson's ratio. However, there is a strong research interest in developing and studying engineering materials with negative Poisson's ratios (NPR) [1][2][3][4][5][6] and zero Poisson's ratios (ZPR) [7][8][9].…”