Mechanical characterization of scalp tissue through suction tests: A feasibility study based on a combined experimental and modeling approach

• A suction device estimates in situ elasticity of the porcine scalp complex • A closed-form model provides a first-order approximation of scalp stiffness • Coupling suction and simulation separates skin and fasciae contributions • The method overcomes ex vivo testing limits for fasciae characterization • The contribution of subcutaneous tissues should not be neglected in scalp models Fasciae are ubiquitous living tissues located between the skin and subcutaneous structures such as bones and muscles. Their mechanical properties are difficult to characterize, as ex vivo testing often fails to reproduce their in situ behaviour. This study explores the feasibility of using a hybrid approach involving a custom large-diameter suction device and different original modelling approaches to probe the mechanical contribution of the scalp, including skin and subcutaneous fasciae. First, we assess the ability of a simple closed-form solution to estimate the elastic properties of the scalp complex and to reproduce experimental data on different soft synthetic and biological materials selected as case studies. Secondly, using a recently developed computational simulation of the skin-to-bone interface, we examine the contribution of subcutaneous fasciae to the overall suction response. Our findings suggest that (i) the suction test, combined with a basic mathematical model, has the potential to provide an in situ estimate of the effective elastic properties of the scalp complex, and (ii) integrating the suction device with a computational model of skin-to-bone interaction may allow the mechanical contribution of the skin to be distinguished from that of deeper supporting tissues. As a feasibility study, this work establishes a methodological foundation for further non-invasive characterization of scalp tissue. Future applications will focus on clinically relevant conditions, particularly the investigation of scalp mechanics during vacuum-assisted delivery with the long-term objective of better understanding and reducing suction-related neonatal injuries.