Near-field optical techniques have enabled the trapping, transport, and handling 
of nanoscopic materials much smaller than what can be manipulated with 
traditional optical tweezers. Here we extend the scope of what is possible by 
demonstrating angular orientation and rotational control of both biological and 
nonbiological nanoscale rods using photonic crystal nanotweezers. In our 
experiments, single microtubules (diameter 25 nm, length 8 μm) and multiwalled 
carbon nanotubes (outer diameter 110-170 nm, length 5 μm) are rotated by the 
optical torque resulting from their interaction with the evanescent field 
emanating from these devices. An angular trap stiffness of κ = 92.8 
pN·nm/rad(2)·mW is demonstrated for the microtubules, and a torsional spring 
constant of 22.8 pN·nm/rad(2)·mW is measured for the nanotubes. We expect that 
this new capability will facilitate the development of high precision 
nanoassembly schemes and biophysical studies of bending strains of biomolecules.