Résumé
We will discuss recent results: (i) on the theory of the Casimir torque between two gratingsrotated by an angle θ with respect to each other [1]; and (ii) on the theory and experimenton the Casimir force between interpenetrating gratings [2]. These findings pave the way tothe design of contactless quantum vacuum torsional spring and sensors with possiblerelevance to micro and nanomechanical devices.