Mechanical properties of microcapsules used in a self-healing polymer

The elastic modulus and failure behavior of poly(urea-formaldehyde) shelled microcapsules were determined through single-capsule compression tests. Capsules were tested both dry and immersed in a fluid isotonic with the encapsulant. A shell-theory model for a fluid-filled microcapsule was utilized to extract the modulus of the shell wall material from individual capsule tests. The testing of capsules immersed in a fluid had little influence on mechanical behavior in the elastic regime. The average capsule shell wall modulus was determined to be 3.7 GPa. Capsule diameter was found to have a significant effect on burst strength, with smaller capsules sustaining higher stresses before burst.published or submitted for publicationis peer reviewe

Heterogeneous Red Blood Cell Adhesion and Deformability in Sickle Cell Disease

We present a microfluidic approach that allows simultaneous interrogation of RBC properties in physiological flow conditions at a single cell level. With this method, we studied healthy hemoglobin A (HbA) and homozygous sickle hemoglobin (HbS) containing RBCs using whole blood samples from twelve subjects. We report that HbS-containing RBCs are heterogeneous in terms of adhesion and deformability in flow