ABSTRACT
Since their first appearance in the 1970s (Ashkin, 1970), optical
tweezers (OT) have been extensively developed and have proved
to be an invaluable tool for a variety of applications throughout
the biophysical sciences (Ashkin and Dziedzic, 1987; Block et al.,
1989; Finer et al., 1994; Mehta et al., 1999; Meyer et al., 2006;
Tskhovrebova et al., 1997; Yoon et al., 2008). This success relies
essentially on the fact that OT can be considered as exceptionally
sensitive mechanical transducers able to resolve pN forces and nm displacements, with high temporal resolution (down to μsec); offer-
ing to a broad scientific community the opportunity of mechanically
sensing the systems’ dynamics at relatively small length scales, i.e.,
down to a molecular level. Hence, the rheological interest of OT
for inverting the classical top-bottom approach of bulk-rheology
measurements addressed to investigate the molecular dynamics.
Indeed, with the advent of OT, rheologists have the opportunity of
a newmechanical tool for measuring single molecular dynamics and
developing bottom-up rheological models aimed at predicting the
bulk-flow of matter.
