In impedance cytometry, particle trajectory can influence the measurements obtained. In this review, the physical grounds of this dependence are explained and both the challenges and the opportunities induced by this phenomenon are discussed.

Although robotic micromanipulation using microtweezers has been widely explored, the current manipulation throughput hardly exceeds one operation per second. Increasing the manipulation throughput is thus a key factor for the emergence of robotized microassembly industries. This article presents MiGriBot (Millimeter Gripper Robot), a miniaturized parallel robot with a configurable platform and soft joints, designed to perform pick-and-place operations at the microscale. MiGriBot combines in a single robot the benefits of a parallel kinematic architecture with a configurable platform and the use of soft joints at the millimeter scale. The configurable platform of the robot provides an internal degree of freedom that can be used to actuate microtweezers using piezoelectric bending actuators located at the base of the robot, which notably reduces the robot’s inertia. The soft joints make it possible to miniaturize the mechanism and to avoid friction. These benefits enable MiGriBot to reach a throughput of 10 pick-and-place cycles per second of micrometer-sized objects, with a precision of 1 micrometer.

International audienceDuring microscale object manipulation, contact (pull-off) forces and non-contact (capillary, van der Waals and electrostatic) forces determine the behaviour of the micro-objects rather than the inertial forces. The aim of this article is to give an experimental analysis of the physical phenomena at a microscopic scale in dry and liquid media. This article introduces a review of the major differences between dry and submerged micromanipulations. The theoretical influences of the medium on van der Waals forces, electrostatic forces, pull-off forces and hydrodynamic forces are presented. Experimental force measurements based on an AFM system are carried out. These experiments exhibit a correlation better than 40 % between the theoretical forces and the measured forces (except for pull-off in water). Finally, some comparative experimental micromanipulation results are described and show the advantages of the liquid medium

ThermoBot uses a laser-induced thermocapillary flow to manipulate floating micro-objects and assist self-assemblies.

The development of reliable and repeatable strategies to manipulate and assemble microobjects lies in the efficiency, reliability, and precision of the handling processes. In this paper, we propose a thermal-based microgripper working in an aqueous medium. Manipulating and assembling in liquid surroundings can indeed be more efficient than in dry conditions. A comparative analysis of the impact of dry and liquid media on surface forces, contact forces, and hydrodynamic forces is shown. In addition, ice grippers represent flexible manipulation solutions. Nevertheless, when micromanipulation tasks are performed in air, capillary forces can drastically perturb the release. Our submerged freeze microgripper exploits the liquid surroundings to generate an ice droplet to catch microobjects, and to avoid capillary forces during the release. The thermal principle, the first microgripper prototype, an ice generation simulation, and the first tests are presented. The main objective is to validate the manipulation principle. Further research will be focused on control and optimization of the ice generation and the miniaturization of the system.