Optical trapping of (sub)micron-sized
particles is broadly employed
in nanoscience and engineering. The materials commonly employed for
these particles, however, have physical properties that limit the
transfer of linear or angular momentum (or both). This reduces the
magnitude of forces and torques, and the spatiotemporal resolution,
achievable in linear and angular traps. Here, we overcome these limitations
through the use of single-crystal rutile TiO2, which has
an exceptionally large optical birefringence, a high index of refraction,
good chemical stability, and is amenable to geometric control at the
nanoscale. We show that rutile TiO2 nanocylinders form
powerful joint force and torque transducers in aqueous environments
by using only moderate laser powers to apply nN·nm torques at
kHz rotational frequencies to tightly trapped particles. In doing
so, we demonstrate how rutile TiO2 nanocylinders outperform
other materials and offer unprecedented opportunities to expand the
control of optical force and torque at the nanoscale.