The mucus clearance system is the dominant mechanical host defense system of the human
lung. Mucus is cleared from the lung by cilia and airflow, including both two-phase gas-liquid …

Dynamic light scattering (DLS) has evolved as a fast, convenient tool for particle size
analysis of noninteracting spherical colloids. In this historical review, we discuss the basic …

Living systems operate far from thermodynamic equilibrium. Enzymatic activity can induce
broken detailed balance at the molecular scale. This molecular scale breaking of detailed …

Single-molecule force spectroscopy has emerged as a powerful tool to investigate the forces
and motions associated with biological molecules and enzymatic activity. The most common …

In microrheology, the local and bulk mechanical properties of a complex fluid are extracted
from the motion of probe particles embedded within it. In passive microrheology, particles …

The field of microrheology is concerned with how materials store and dissipate mechanical
energy as a function of length scale. Recent developments in the theory and instrumentation …

In an optical tweezers experiment intense laser light is tightly focused to intensities of
MW/cm 2 in order to apply forces to submicron particles or to measure mechanical …

Microorganisms can form biofilms, which are multicellular communities surrounded by a
hydrated extracellular matrix of polymers. Central properties of the biofilm are governed by …

Soft microgel particles inherently possess qualities of both polymers as well as particles. We
review the similarities and differences between soft microgel particles and stiff colloids at …

When an indenter is pressed into a gel to a fixed depth, the solvent in the gel migrates, and
the force on the indenter relaxes. Within the theory of poroelasticity, the force relaxation …