Determining the mechanical properties of rat skin with digital image speckle correlation.
BACKGROUND
Accurate measurement of the mechanical properties of skin has numerous implications in surgical repair, dermal disorders and the diagnosis and treatment of trauma to the skin. Investigation of facial wrinkle formation, as well as research in the areas of skin aging and cosmetic product assessment can also benefit from alternative methodologies for the measurement of mechanical properties.


OBJECTIVE
A noncontact, noninvasive technique, digital image speckle correlation (DISC), has been successfully introduced to measure the deformation field of a skin sample loaded by a material test machine. With the force information obtained from the loading device, the mechanical properties of the skin, such as Young's modulus, linear limitation and material strength, can be calculated using elastic or viscoelastic theory.


METHODS
The DISC method was used to measure the deformation of neonatal rat skin, with and without a glycerin-fruit-oil-based cream under uniaxial tension.


RESULTS
Deformation to failure procedure of newborn rat skin was recorded and analyzed. Single skin layer failures were observed and located by finding the strain concentration. Young's moduli of freshly excised rat skin, cream-processed rat skin and unprocessed rat skin, 24 h after excision, were found with tensile tests to be 1.6, 1.4 and 0.7 MPa, respectively.


CONCLUSIONS
Our results have shown that DISC provides a novel technique for numerous applications in dermatology and reconstructive surgeries.
Guan
E
E
Department of Materials Science and Engineering, State University of New York, Stony Brook, NY 11794, USA. eguan@ic.sunysb.edu
Smilow
Sarah
S
Rafailovich
Miriam
M
Sokolov
Jonathan
J
D000818:Animals; D000831:Animals, Newborn; D046508:Culture Techniques; D003952:Diagnostic Imaging / Q000379:methods*; D004548:Elasticity; D004817:Epidermis / Q000033:anatomy & histology / Q000648:ultrastructure; D005260:Female; D008297:Male; D051381:Rats; D012680:Sensitivity and Specificity; D012867:Skin / Q000033:anatomy & histology / Q000648:ultrastructure*; D012879:Skin Physiological Phenomena; D013314:Stress, Mechanical; D013718:Tensile Strength