Capillary force disturbances on a partially submerged cylindrical micromanipulator.

International audienceThe objective of this article is to analyse the impact of liquid surface tension on force measurement in submerged micromanipulation. Firstly, at the present, mechanical characterization of biological objects in biological liquid has significant interest. Secondly, the reduction of the surface force and adhesion forces in a submerged medium could be a relevant approach to perform reliable artificial objects micromanipulation. In both cases, the mico-nano force measurement in a liquid is a great challenge. In case of a force sensor placed out of the liquid, the measurement is disturbed by the liquid surface tension. This article proposes an analysis of these disturbances on force measurements. Some design rules are proposed to reduce disturbances. We show that the major disturbances are induced by the contact angle hysteresis and a complete method is proposed to calculate these disturbances in a micromanipulation task