1. Introduction
Mechanical propertiesplayasignificant roleinthefunctionof
manytissuesandalsointheperformanceofimplantedgraftsand
tissue engineeringscaffolds.Inparticular,thereisconvincing
evidence thatthedynamicmechanicalcompliancepropertiesof
vascularbypassgraftsinfluence theirlongtermprospectsofbe-
coming re-occludedwithplaqueorthrombus(Fig. 1) [1]. Com-
pliance relatesvesseldilationtochangesor fluctuations ininternal
pressure,anditisknowntoaffectthehemodynamicsofpulsatile
blood flow andhencethemechanicalregimeexperiencedbycells
in theendotheliumandvesselwall [2].
Fornaturalarteries,complianceisfoundtodependinanon-
linear fashiononthemeanpressureofthepulsatileblood flow
(e.g. femoralartery, Fig. 2(a) [3]). Thisnon-linearresponsemod-
ulates theelasticresponseofthearteryinresponsetoalteredor
heightenedpressureregimeswithprogressivelyreducingcom-
pliance. Thischaracteristicisnot,however,reflected inmany
synthetic graftswhichexhibitrelativelyconstantcomplianceover
a widerangeofphysiologicalorpathologicalmeanbloodpres-
sures (e.g.PTFEgraft, Fig. 2(a, b)) [1,3].