title: Use of rigid spherical inclusions in Young's moduli determination: application to DNA-crosslinked gels.
abstract: Current techniques for measuring the bulk shear or elastic (E) modulus of small samples of soft materials are usually limited by materials handling issues. This paper describes a nondestructive testing method based on embedded spherical inclusions. The technique simplifies materials preparation and handling requirements and is capable of continuously monitoring changes in stiffness. Exact closed form derivations of E as functions of the inclusion force-displacement relationship are presented. Analytical and numerical analyses showed that size effects are significant for medium dimensions up to several times those of the inclusion. Application of the method to DNA-crosslinked gels showed good agreement with direct compression tests.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Lin
authors.forename: Bernard
authors.initials: B
authors.lastname: Yurke
authors.forename: Noshir A
authors.initials: NA
authors.lastname: Langrana
mesh_terms: D000180:Acrylic Resins / Q000032:analysis / Q000737:chemistry*; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry; D003198:Computer Simulation; D003432:Cross-Linking Reagents / Q000737:chemistry; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D004548:Elasticity; D006244:Hardness; D006245:Hardness Tests / Q000379:methods*; D008280:Magnetics; D008422:Materials Testing / Q000379:methods*; D008863:Microspheres; D008956:Models, Chemical; D010812:Physical Stimulation / Q000379:methods*; D013314:Stress, Mechanical
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; C016680:polyacrylamide gels; D004247:DNA