AbstractThis research aimed to optically trap and manipulate a single calix[4]arene
microcluster in water. The optically trapped microclusters were evaluated in terms of
their optical stiffness and rotatability with respect to the variation of microclusters'
effective radius and laser power density. The calixarene microclusters contained
solution was prepared by sonicating a vial containing a mixture of 1.7 mg of
calix[4]arene powder in 1 ml of deionised water for three minutes. Calix[4]arene
microclusters in the effective radius range between 0.5 and 3.5 μm were optically
trapped using a 976 nm laser at laser power densities between 0.67 and 2.30 MW/cm2
with laser sport size 1.1 μm. A quadrant photodiode (QPD) collected the scattered
light from a single trapped microcluster. The QPD signal was analysed using a
custom-made program named OSCal to determine the corner frequency of the optical
trap. A quarter waveplate was introduced to the laser path to change the laser
polarisatio.....