Comparison of Noninvasive Imagery Methods to Observe Healthy and Degenerated Olfactory Epithelium in Mice for the Early Diagnosis of Neurodegenerative Diseases.

Olfactory dysfunction could be an early and reliable indicator for the diagnosis of neurodegenerative disorders such as Alzheimer and Parkinson's diseases. In this paper, we compare the potential of different noninvasive medical imaging modalities (optical coherence tomography, confocal microscopy, and fluorescence endomicroscopy) to distinguish how the olfactory epithelium, both at the cellular and the structural levels, is altered. Investigations were carried out on three experimental groups: two pathological groups (mice models with deliberately altered olfactory epithelium and Alzheimer's disease transgenic mice models) were compared with healthy mice models. As histological staining, the three tested noninvasive imaging tools demonstrated the general tubular organization of the olfactory epithelium on healthy mice. Contrary to OCT, confocal microscopy, and endomicroscopy allowed visualizing the inner structure of olfactory epithelium as well as its morphological or functional changes on pathological models, alterations classically observed with histological assessment. The results could lead to relevant development of imaging tools for noninvasive and early diagnosis of neurodegenerative diseases through the in situ characterization of the olfactory epithelium.

Toward Conductive Polymer-Based Soft Milli-Robots for Vacuum Applications.

For the last two decades, the development of conducting polymers (CP) as artificial muscles, by materials researchers and chemists, has made establishing a reliable and repeatable synthesis of such materials possible. CP-based milli-robots were mostly unknown in soft robotics, however, today, they play a vital role in robotics and smart materials forums. Indeed, this subclass of soft robots has reached a crucial moment in their history, a moment where they can display rather interesting features, based on established foundations in terms of modeling, control, sensing, and planning in various applications. The purpose of this paper is to present the potential of conductive polymer-based soft milli-robots as high-performance devices for vacuum applications. To that end, a trilayer polypyrrole-based actuator was first used inside a scanning electron microscope (SEM), characterized for different applied voltages, over a relatively long period. Additionally, the tip positioning of the cantilever was also controlled using a closed-loop control. Furthermore, as a proof of concept for more complex soft milli-robots, an S-shaped soft milli-robot was modeled, using a hybrid model comprised of two models; a multi-physics model and a kinematic model. It was then fabricated using laser machining and finally characterized using its tip displacement. polypyrrole-based soft milli-robots proved to have tremendous potential as high-performance soft robots at the microscale for a wide range of applications, including SEM micro-manipulation as well as biomedical applications.

Developments and Control of Biocompatible Conducting Polymer for Intracorporeal Continuum Robots.

Dexterity of robots is highly required when it comes to integration for medical applications. Major efforts have been conducted to increase the dexterity at the distal parts of medical robots. This paper reports on developments toward integrating biocompatible conducting polymers (CP) into inherently dexterous concentric tube robot paradigm. In the form of tri-layer thin structures, CP micro-actuators produce high strains while requiring less than 1 V for actuation. Fabrication, characterization, and first integrations of such micro-actuators are presented. The integration is validated in a preliminary telescopic soft robot prototype with qualitative and quantitative performance assessment of accurate position control for trajectory tracking scenarios. Further, CP micro-actuators are integrated to a laser steering system in a closed-loop control scheme with displacements up to 5 mm. Our first developments aim toward intracorporeal medical robotics, with miniaturized actuators to be embedded into continuum robots.

Adhesion control for micro- and nanomanipulation.

The adhesion between a micro/nano-object and a microgripper end-effector is an important problem in micromanipulation. Canceling or reducing this force is a great challenge. This force is directly linked to the surface chemical structure of the object and the gripper. We propose to predict this force between a structuring surface and a micro-object with a multisphere van der Waals force model. The surface was structured by polystyrene latex particles (PS particles) with radii from 35 to 2000 nm. The model was compared with experimental pull-off force measurements performed by AFM with different natures of spheres materials glued on the tipless. A wide range of applications, in the field of telecommunications, bioengineering, and more generaly speaking MEMS can be envisaged for these substrates.

Reducing the adhesion between surfaces using surface structuring with PS latex particle.

The adhesion between a micro-object and a microgripper end-effector is an important problem in micromanipulation. Canceling or reducing this force is a great challenge. This force is directly linked to the surface chemical structure of the object and the gripper. We propose to reduce the adhesion force by using a self-assembled monolayer structuring on one surface. The surface was structured by polystyrene latex particles (PS particles) with radii from 100 to 1500 nm. The adhesion force measurements obtained by AFM were compared to a multisphere van der Waals force model. The model suggests the existence of an optimal value of the sphere radius which minimizes the adhesion. In that case, the pull-off force is reduced to 20 nN by the PS particles layer with a radius of 45 nm. A wide range of applications in the field of telecommunications, bioengineering, and more generally speaking, MEMS can be envisaged for these substrates.

Adhesion forces controlled by chemical self-assembly and pH: application to robotic microhandling.

Robotic microhandling is a promising way to assemble microcomponents in order to manufacture a new generation of hybrid microelectromechanical systems. However, at the scale of several micrometers, the adhesion phenomenon highly perturbs the micro-object release and positioning. This phenomenon is directly linked to both the object and the gripper surface chemical composition. We propose to control the adhesion by using a chemical self-assembled monolayer on both surfaces. Different types of chemical functionalization have been tested, and this paper focuses on the presentation of aminosilane-grafted 3-(ethoxydimethylsilyl)propylamine and (3-aminopropyl)triethoxysilane. We show that the liquid pH can be used to modify the adhesion and to switch from an attractive behavior to a repulsive behavior. The pH control can thus be used to increase the adhesion during handling and cancel the adhesion during release. Experiments have shown that the pH control is able to control the release of a micro-object. This paper shows the relevance of a new type of reliable submerged robotic microhandling principle, which is based on adjustment of the chemical properties of the liquid.