Many biological materials exist as micro-scale particles such as blood cells, liposomes for drug delivery, and fat globules in milk. The mechanical properties of these particles can play a major role in their function in the body. However, because of their small size they have been difficult to characterize using traditional techniques. Our lab has developed a new instrument called a Cantilevered-Capillary Force Apparatus (CCFA) that is capable of measuring and applying forces from 1 nN to 1 mN on particles ranging in size from 10 microns to 1 mm. In this talk I will describe the working principles of this new instrument and give examples of how it has been used for a few specific cases including measurements of adhesion between multilamellar vesicles, stress relaxation in model fat globules, and the elastic modulus of edible polymer microcapsules. |