The penetration of a soft solid by a liquid jet, with application to the administration of a needle-free injection.
Liquid jet injections have been performed on human skin in vivo and silicone rubber using Intraject needle-free injectors. The discharge characteristics of the liquid jet were measured using a custom-built test instrument. The experiments reveal that a high-speed liquid jet penetrates a soft solid by the formation and opening of a planar crack. The fluid stagnation pressure required for skin penetration decreases with increasing diameter of the liquid jet. These findings are consistent with the slow-speed penetration of a soft solid by a sharp-tipped punch. It is demonstrated that the Shergold-Fleck sharp-tipped punch penetration model [Shergold, O.A., Fleck, N.A., 2004. Mechanisms of deep penetration of soft solids. Proc. Roy. Soc. Lond. A 460, 3037-3058.] gives adequate predictions for the pressure required to penetrate a soft solid by a high-speed liquid jet.
Shergold
Oliver A
OA
Cambridge University Engineering Department, Trumpington St., Cambridge, CB2 1PZ, UK.
Fleck
Norman A
NA
King
Toby S
TS
D001696:Biomechanical Phenomena; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007277:Injections, Jet / Q000295:instrumentation / Q000379:methods; D008962:Models, Theoretical; D011312:Pressure; D011677:Punctures; D033081:Shear Strength; D012826:Silicone Elastomers / Q000737:chemistry; D012867:Skin / Q000503:physiopathology*; D014950:Wounds, Penetrating / Q000503:physiopathology*
D012826:Silicone Elastomers