TY - JOUR
T1 - Allometric scaling of skin thickness, elasticity, viscoelasticity to mass for micro-medical device translation
T2 - From mice, rats, rabbits, pigs to humans
AU - Wei, Jonathan C.J.
AU - Edwards, Grant A.
AU - Martin, Darren J.
AU - Huang, Han
AU - Crichton, Michael L.
AU - Kendall, Mark A.F.
N1 - Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Emerging micro-scale medical devices are showing promise, whether in delivering drugs or extracting diagnostic biomarkers from skin. In progressing these devices through animal models towards clinical products, understanding the mechanical properties and skin tissue structure with which they interact will be important. Here, through measurement and analytical modelling, we advanced knowledge of these properties for commonly used laboratory animals and humans (~30 g to ~150 kg). We hypothesised that skin's stiffness is a function of the thickness of its layers through allometric scaling, which could be estimated from knowing a species' body mass. Results suggest that skin layer thicknesses are proportional to body mass with similar composition ratios, inter-and intra-species. Experimental trends showed elastic moduli increased with body mass, except for human skin. To interpret the relationship between species, we developed a simple analytical model for the bulk elastic moduli of skin, which correlated well with experimental data. Our model suggest that layer thicknesses may be a key driver of structural stiffness, as the skin layer constituents are physically and therefore mechanically similar between species. Our findings help advance the knowledge of mammalian skin mechanical properties, providing a route towards streamlined micro-device research and development onto clinical use.
AB - Emerging micro-scale medical devices are showing promise, whether in delivering drugs or extracting diagnostic biomarkers from skin. In progressing these devices through animal models towards clinical products, understanding the mechanical properties and skin tissue structure with which they interact will be important. Here, through measurement and analytical modelling, we advanced knowledge of these properties for commonly used laboratory animals and humans (~30 g to ~150 kg). We hypothesised that skin's stiffness is a function of the thickness of its layers through allometric scaling, which could be estimated from knowing a species' body mass. Results suggest that skin layer thicknesses are proportional to body mass with similar composition ratios, inter-and intra-species. Experimental trends showed elastic moduli increased with body mass, except for human skin. To interpret the relationship between species, we developed a simple analytical model for the bulk elastic moduli of skin, which correlated well with experimental data. Our model suggest that layer thicknesses may be a key driver of structural stiffness, as the skin layer constituents are physically and therefore mechanically similar between species. Our findings help advance the knowledge of mammalian skin mechanical properties, providing a route towards streamlined micro-device research and development onto clinical use.
UR - http://www.scopus.com/inward/record.url?scp=85034777164&partnerID=8YFLogxK
U2 - 10.1038/s41598-017-15830-7
DO - 10.1038/s41598-017-15830-7
M3 - Article
SN - 2045-2322
VL - 7
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 15885
ER -