Microrheology probes length scale dependent rheology.
نویسندگان
چکیده
We exploit the power of microrheology to measure the viscoelasticity of entangled F-actin solutions at different length scales from 1 to 100 microm over a wide frequency range. We compare the behavior of single probe-particle motion to that of the correlated motion of two particles. By varying the average length of the filaments, we identify fluctuations that dissipate diffusively over the filament length. These provide an important relaxation mechanism of the elasticity between 0.1 and 30 rad/sec.
منابع مشابه
Microrheology of Complex Fluids
Many of the diverse material properties of soft materials (polymer solutions, gels, filamentous proteins in cells, etc.) stem from their complex structures and dynamics with multiple characteristic length and time scales. A wide variety of technologies, from paints to foods, from oil recovery to processing of plastics, all heavily rely on the understanding of how complex fluids flow (Larson, 19...
متن کاملRheological microscopy: local mechanical properties from microrheology.
We demonstrate how tracer microrheology methods can be extended to study submicron scale variations in the viscoelastic response of soft materials; in particular, a semidilute solution of lambda-DNA. The polymer concentration is depleted near the surfaces of the tracer particles, within a distance comparable to the polymer correlation length. The rheology of this microscopic layer alters the tr...
متن کاملMicrorheology and the fluctuation theorem in dense colloids
We present experiments and computer simulations of a “tracer” (or “probe”) particle trapped with optical tweezers and dragged at constant speed through a bath of effectively hard colloids with approximately the same size as the probe. The results are analyzed taking the single-particle case and assuming effective parameters for the bath. The effective microscopic friction coefficient and effect...
متن کاملMicrorheology of cross-linked polyacrylamide networks.
Experiments investigating the local viscoelastic properties of a chemically cross-linked polymer are performed on polyacrylamide solutions in the sol and the gel regimes using polystyrene beads of varying sizes and surface chemistry as probes. The thermal motions of the probes are measured to obtain the elastic and viscous moduli of the sample. Probe dynamics are measured using two different dy...
متن کاملProbing linear and nonlinear microrheology of viscoelastic fluids
Bulk rheological properties of viscoelastic fluids have been extensively studied in macroscopic shearing geometries. However, little is known when an active microscopic probe is used to locally perturb them far from the linear-response regime. Using a colloidal particle dragged periodically by scanning optical tweezers through a viscoelastic fluid, we investigate both, its linear and nonlinear ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 96 11 شماره
صفحات -
تاریخ انتشار 2006