D. Sinan Haliyo

[mü]MAD, the adhesion based dynamic micro-manipulator

In this paper, a micro-manipulation method based on adhesion forces and dynamic effects is proposed. A prototype manipulator, called [mu]MAD, has been constructed and successfully experimented. Moreover, the advanced capabilities of [mu]MAD, especially two new interesting applications, are presented: sorting of micro-objects and mechanical characterizations.

Electro-osmotic propulsion of helical nanobelt swimmers

Micro and nanoscale mobile agents capable of self-propulsion in low Reynolds number fluids would have a great technological impact in many fields. Few known mechanisms are able to propel such devices. Here we describe helical nanobelt (HNB) swimmers actuated by an electric field-generated electro-osmotic force. These HNB swimmers are designed with a head and a tail, similar to natural micro-organisms such as bacteria and their flagella. We show that these electro-osmotic propulsion of HNB swimmers achieve speeds (24 body lengths per second), force (1.3 nN), and pressure (375.5 Pa) above those demonstrated by other artificial swimmers based on physical energy conversion. Although nature’s bacteria are still more dynamic, this paper reports that the demonstrated electro-osmotic HNB microswimmers made a big step toward getting closer to their performances. Moreover, an unusual swimming behavior with discontinuous pumping propulsion, similar to jellyfish, was revealed at or above the speculated marginal limit of linear propulsion. These electro-osmosis propelled HNB swimmers might be used as biomedical carriers, wireless manipulators, and as local probes for rheological measurements.

Haptic interface transparency achieved through viscous coupling

Electromagnetic drives are subjected to an inherent inertia–torque tradeoff that fundamentally limits transparency: the higher the torque, the higher the inertia. We describe a dual-stage design that is not subjected to this tradeoff and that is able to approach perfect transparency for human users. It comprises a large, proximal motor and a small, distal motor to reproduce the transients. The two stages are coupled by a viscous clutch based on eddy currents that, without contact, accurately transforms slip velocity into torque. Such a system can, in general, be controlled to achieve a variety of objectives. Here, we show that an advanced, discrete-time, RST polynomial pole-placement controller can achieve near-perfect transparency. Experimental validation evaluated the human ability to detect small haptic details when using this drive and compared it with when using a conventional, single-motor interface.

The ultimate haptic device: First step

We describe a single-axis haptic interface which is based on a dual-stage actuator technique and which is aimed at achieving perfect transparency to a human user. The paper shows how all parasitic forces arising from inertia and friction can be brought below human detection thresholds, yet, the system is able to output significant torque. It has a stage with a large motor coupled to a distal stage with a smaller motor via a viscous coupler based on the principle of eddy current induction. The paper also describes its control principle and preliminary results.

Controlled rolling of microobjects for autonomous manipulation

This paper presents our work in developing an autonomous micromanipulation system. The originality of our system is that it takes advantage of adhesion forces to grip micro-objects using an AFM (Atomic Force Microscopy) probe. A theoretical analysis of rolling conditions is carried out in order to achieve precise release of an object picked-up by adhesion. Vision control, based on the specificities of optical microscopy, and force control, based on the analysis of the AFM probe, are established. Experiments validate the employed techniques and the proposed manipulation mode.

Remotely Powered Propulsion of Helical Nanobelts

Reynolds number fluids would have a big technological impact in many fields. Few known mechanisms are able to propel such devices. Here we demonstrate that helical nanobelts can swim in liquid when actuated by an electric field generated by electro-osmotic force. Moreover, we show these devices achieve speeds at or slightly above those demonstrated by natural bacteria. The helical nanobelts were designed and fabricated with a head and tail to mimic natural microorganisms such as bacteria and their flagellae. The electro-osmotic propulsion of helical nanobelts might be used as biomedical carriers, wireless manipulators, and as local probes for rheological measurements.

Improving Perception and Understanding of Nanoscale Phenomena Using Haptics and Visual Analogy

This paper introduces a new pedagogical tool using haptic feedback and visual analogy, to improve perception and learning of nanoscale phenomena, for people without prior knowledge of nanophysics. This tool is a haptic and virtual-reality simulator of a foremost one-dimensional nanophysical phenomenon: the approach-retract cycle of an Atomic Force Microcope (AFM) probe, with a force-feedback device and two graphic representations. One representation is a virtual AFM cantilever and the other one is a virtual magnet-spring system, whose haptic behavior is analog. Preliminary results from an experiment conducted with forty-five students seem to show a better efficiency with the combination of both haptic feedback and visual analogy.

Remote microscale teleoperation through virtual reality and haptic feedback

This paper reports the remote handling of microscale objects, between two sites approximately 630 km distant. To manipulate objects less than 10 µm, specific equipments such as AFM (Atomic Force Microscope) cantilevers integrated into a SEM (Scanning Electron Microscope) are generally required. Enabling remote access to such a system would benefit any micro/nanoresearcher. However, vision feedback and sensor data of a micromanipulation system are generally limited, hence the implementation of a teleoperation scenario is not straightforward. Specific tools are proposed here for an intuitive manipulation in a wide range of applications. To ensure ease of manipulation, both a 3D virtual representation of the scene and haptic feedback are provided. Force sensor feedback is limited since only two measures are available. In order to extend this information, vision algorithms are developed to estimate the respective positions of the tool and objects, which are then used to calculate the haptic feedback. The stability of the overall scheme is very sensitive to time delays. This requirement is taken into account in vision algorithms and the communication module which transfers the data between the two remote sites. In addition, the proposed robotic control architecture is modular so that the platform can be used for a wide range of applications. First results are obtained on a teleoperation between Paris, France, and Oldenburg, Germany.

3D haptic handling of microspheres

In this paper, a fully teleoperated 3D micro assembly task with haptic feedback is presented. Microspheres (diameter: 4–6µm) are manipulated by pick-and-place. The setup is composed of a dual-tip gripper controlled through a haptic interface. To grasp the spheres, the tips must be correctly positioned with respect to the objects. The approach proposed to align the gripper is based on a user-driven exploration of the tobe-manipulated object. During this step, the haptic feedback is based on amplitude measurements from cantilevers in dynamic mode. Hence, the operator perceives the contact while freely exploring the manipulation area. A virtual guide is generated to pull the user to the optimum contact point, allowing correct positioning of dual tips. For the pick-and-place operation, the haptic feedback provides the user with information about the microscale interactions occurring during the operation. As experimental validation, a two-layer pyramid composed of four nylon microspheres is built in ambient conditions.

Tuning the gains of haptic couplings to improve force feedback stability in nanorobotics

This paper deals with the problem of bilateral haptic control in nanorobotics. At this scale, a human operator cannot interact directly with objects. He needs special tools manipulated through robotic systems. Therefore, force feedback devices are the only solution to provide him a sense of touch. However, the quality of the rendering strongly influences his ability to perform a given task. Stability is the main requirement that the system must fulfil to be usable. As the choice of the controller and its tuning are critical issues, a general method to tune the parameters of two haptic controllers is presented. A theoretical study is carried out and the methodology is validated with an experiment composed of several phases with high dynamic phenomena. Intrinsic limitations of the two controllers are also pointed out.