Single-cell manipulation is considered a key technology in biomedical research. However, the lack of intuitive and effective systems makes this technology less accessible. We propose a new tele–robotic solution for dexterous cell manipulation through optical tweezers. A slave-device consists of a combination of robot-assisted stages and a high-speed multi-trap technique. It allows for the manipulation of more than 15 optical traps in a large workspace with nanometric resolution. A master-device (6+1 degree of freedom (DoF)) is employed to control the 3D position of optical traps in different arrangements for specific purposes. Precision and efficiency studies are carried out with trajectory control tasks. Three state-of-the-art experiments were performed to verify the efficiency of the proposed platform. First, the reliable 3D rotation of a cell is demonstrated. Secondly, a six-DoF teleoperated optical-robot is used to transport a cluster of cells. Finally, a single-cell is dexterously manipulated through an optical-robot with a fork end-effector. Results illustrate the capability to perform complex tasks in efficient and intuitive ways, opening possibilities for new biomedical applications.
28 January 2020 in IEEE Robotics and Automation Letters
Micro-teleoperated interaction with biological cells is of special interest. The low fidelity of previous systems aimed at such small scale tasks prompted the design of a novel manual bilateral cell injection system. This systems employed the coupling of a null-displacement active force sensor with a haptic device having negligible effective inertia. This combination yielded a bilateral interaction system that was unconditionally stable even when the scaling gains were high. To demonstrate the capability of this system, two experiments were performed. A hard trout egg was delicately punctured and a small dye amount was injected in an embryo within a zebra fish egg without causing other forms of damage. The results demonstrate that the system let an operator dextrously interact with reduced reliance on visual feedback.
We describe a manually operated, bilateral mechanical scaling instrument that simultaneously magnifies microscopic forces and reduces displacements with quasi-perfect transparency. In contrast with existing micro-teleoperation designs, the system is unconditionally stable for any scaling gains and interaction curves. In the present realization, the work done by the hand is more than a million times that done by a microscopic probe so that one can feel complete interaction cycles with water and compare them to what is felt when an insect leg interacts with a wet surface.
25 June 2020 in IEEE Robotics and Automation Letters
The use of untethered miniature swimmers is a promising trend, especially in biomedical applications. These swimmers are often operated remotely using a magnetic field commonly generated using fixed coils that can suffer from a lack of compactness and heating issues. The analysis of the swimming capabilities is still an ongoing topic of research. In this letter, we focus on the ability of a magnetic actuation system to operate the propulsion of miniature swimmers with flexible flagellum. As a first contribution, we present a new manipulability criterion to assess the ability of a magnetic actuation system to operate a swimming robot, i . e . to ensure a displacement in any desired direction with a fixed minimum speed. This criterion is developed thanks to an analogy with cable-driven parallel robots. As a second contribution, this manipulability criterion is exploited to identify the dexterous swimming workspace which can be used to design of new coil configurations as well as to highlight the possibilities of moving coil systems. A case study for a planar workspace surrounded by three coils is in particular carried out. The accompanying video illustrates the application of the proposed criterion in 3D, for a large number of coils.
17 November 2023 in IEEE Robotics and Automation Letters
This letter presents a method to determine and control the center of rotation of a parallel micro-robotic platform used as a sample holder for an Atomic Force Microscope (AFM). The AFM is operating inside a Scanning Electron Microscope (SEM) for correlative AFM in SEM imaging. The objective is to spatially co-localize the Pivot Point (PP) and the AFM tip at any region of interest of a sample within the reachable workspace of the AFM. To do so, SEM images are used to land the AFM tip on a desired Point Of Interest (POI). Topographic data obtained with the AFM are used to calculate the Tool Center Point (TCP) of the robot and to identify the coordinates of the POI in the AFM sample holder reference frame. The position of the PP is then controlled relying on the TCP and SEM vision to finally been able to perform, in a controlled way, in-plane rotations of the sample holder around the AFM tip with a micrometer precision. This work shows for the first time how SEM and AFM data can be used in tandem to calibrate the rotational degrees of freedom of an AFM system.