Here, the thermophoretic force was divided into radially equidistant small regions, and the averaged absolute thermophoretic force within each region was plotted as the representative value for that region. Ideally, in the system where BDS was conducted, the distribution of the temperature gradient should be a function only of the distance r from the laser spot. Consequently, the thermophoretic force should also be a function of r alone. However, in BDS, the temperature and temperature gradient are approximated using the FEM, which may introduce slight variations in the thermophoretic force even at the same distance r. Therefore, to minimize noise caused by these variations and to obtain a smooth curve for the thermophoretic force, we defined the representative value in this way. Additionally, because the viscosity of the fluid 𝜇 is temperaturedependent, an approximate value can be obtained using the approximation shown in Section 2.2, 𝜇 = 2.761exp (1713 𝑇 ⁄ ) Pa s. As a result, the drag coefficient 𝛾 = 6𝜋𝜂𝑎 derived from Stokes' law in equation ( ) also becomes temperature-dependent.