Measurement and Calculation of Casimir Force

Measurement of Casimir force has been progressively improved since the first observation of Casimir force in 1958. In this chapter, we will first introduce our home-built dual-cantilever vacuum system and the detection scheme. We will present the measurement methods and results of Casimir force between two mechanical cantilevers in vacuum. At a separation of x, the Casimir force between an ideally conductive sphere with radius R and an ideally conductive plate is \(F^0_C (x) = -\frac {\pi ^3\hbar c}{360}\frac {R}{x^3}\) . However, we need to consider the finite conductivity, finite temperature, and material dispersion in the calculation. Our measurements agree well with the calculation based on Lifshitz theory. We will also discuss the thermal contributions and the effect of gold thin film thickness on the Casimir force. Parts of the contents in this chapter have been published in Xu et al. (Nat Nanotechnol 17(2):148–152, 2022).