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Wireless capsule endoscopy (WCE) is a powerful tool for medical screening and diagnosis, where a small capsule is swallowed and moved by means of natural peristalsis and gravity through the human gastrointestinal (GI) tract. The camera-integrated capsule allows for visualization of the small intestine, a region which was previously inaccessible to classical flexible endoscopy. As a diagnostic tool, it allows to localize the sources of bleedings in the middle part of the gastrointestinal tract and to identify diseases, such as inflammatory bowel disease (Crohn's disease), polyposis syndrome, and tumors. The screening and diagnostic efficacy of the WCE, especially in the stomach region, is hampered by a variety of technical challenges like the lack of active capsular position and orientation control. Therapeutic functionality is absent in most commercial capsules, due to constraints in capsular volume and energy storage. The possibility of using body-exogenous magnetic fields to guide, orient, power, and operate the capsule and its mechanisms has led to increasing research in Magnetically Guided Capsule Endoscopy (MGCE). This work shortly reviews the history and state-of-art in WCE technology. It highlights the magnetic technologies for advancing diagnostic and therapeutic functionalities of WCE. Not restricting itself to the GI tract, the review further investigates the technological developments in magnetically guided microrobots that can navigate through the various air- and fluid-filled lumina and cavities in the body for minimally invasive medicine.

Future planetary rovers are expected to probe across steep sandy slopes such as crater rims where wheel slippage can be a critical problem. One possible solution is to equip locomotion mechanisms with redundant actuators so that the rovers are able to actively reconfigure themselves to adapt to the target terrain. This study modeled a reconfigurable rover to analyze the effects of posture change on rover slippage over sandy slopes. The study also investigated control strategies for a reconfigurable rover to reduce slippage. The proposed mechanical model consists of two models: a complete rover model representing the relationship between the attitude of the rover and the forces acting on each wheel, and a wheel-soil contact force model expressed as a function of slip parameters. By combining these two models, the proposed joint model relates the configuration of the rover to its slippage. The reliability of the proposed model is discussed based on a comparison of slope-traversing experiments and numerical simulations. The results of the simulations show trends similar to those of the experiments and thus the validity of the proposed model. Following the results, a configuration control strategy for a reconfigurable rover was introduced accompanied by orientation control. These controls were implemented on a four-wheeled rover, and their effectiveness was tested on a natural sand dune. The results of the field experiments show the usefulness of the proposed control strategies.

Electrical properties of Pb(Zr0.53Ti0.47)O3 (PZT) thin films are significantly affected by the film orientation. Especially c-axis-oriented PZT thin films exhibit higher electrical properties. However, perfect orientation control to c-axis is very difficult, especially for the case of chemical solution deposition (CSD). Therefore, we tried to make clear the factors that affect the film orientation of the CSD-derived PZT thin films, by applying the thermal stress. We used stainless steel (SS) substrates with higher thermal expansion coefficients and the CSD-derived LNO seeding layer, which showed good lattice matching with c-plane of PZT and similar thermal expansion coefficient to the SS substrates, to apply the thermal compressive stress to the PZT thin film during cooling. As a result, we successfully deposited the selectively c-axis-oriented PZT thin film with higher remanent polarization, Pr, over 30 μC/cm2 and good squareness of the hysteresis loop. These results elucidate that the thermal compressive stress by the constraint force from substrate is very effective not only for the orientation contol of the resulting PZT thin films but also to improve the electrical properties of the PZT thin films. This strategy is essential to obtain the ferroelectric thin films with excellent electrical properties.

In our photo-induced immobilization technique for an antibody (IgG) using azopolymers, the introduction of COOH and NMe(2) into the azopolymers, which can introduce surface charges, strongly affected the immobilization properties such as the efficiency of immobilization and the activity of the immobilized IgG (i.e., the orientation of the immobilized IgG). The introduction of COOH promoted a more active orientation of the immobilized IgG. The orientation was determined during the adsorption process onto the azopolymer surface in solution before photo-immobilization, and was maintained during the photo-immobilization. The surface charge of the azopolymer appears to be an important factor for IgG orientation, which involves electrostatic interactions between its Fab and the azopolymer surface.

Highly (110)- and (100)-oriented (Pb0.90La0.10)Ti0.975O3 (PLT) thin films were deposited on Pt(111)/Ti/SiO2/Si(100) and SiO2/Si(100) substrates by rf magnetron sputtering with a LaNiO3 (LNO) buffer layer. The LNO buffer layer plays an important role in the orientation and ferroelectric properties of the PLT thin films. Highly (100)-oriented PLT thin films deposited on the LNO/SiO2/Si(100) substrates are obtained at a low processing temperature of 500 °C. The ferroelectric properties of the PLT thin films with different orientations are discussed. Highly (100)-oriented PLT thin films possess better ferroelec- tric properties, with higher remnant polarization (2Pr = 40.4 μC/cm2) and lower coercive field (2Ec = 201 kV/cm) than that of (110)-oriented PLT thin films (2Pr = 22.4 μC/cm2, 2Ec = 246 kV/cm). The enhanced ferroelectric property is attributed to the different orientations of the PLT thin films. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

BiScO3–PbTiO3 (BSPT) thin films were fabricated via a sol–gel method on Pt(111)/Ti/SiO2/Si(111) substrates. The effects of different factors on the orientation of the sol–gel-derived BSPT thin films were investigated. The results showed that a higher lead excess concentration, longer drying time, higher pyrolysis temperature, longer pyrolysis time, higher crystallization temperature, and longer crystallization time could enhance the (100) orientation of the BSPT thin films. Based on the experimental results, a mechanism for the orientation evolution in the sol–gel-derived BSPT thin films was proposed. The production of the (100) orientation was attributed to the (100)-oriented PbO nanocrystals forming during the pyrolysis process due to the lattice match.

Uniform and patterned orientation of a crystallographic direction of ordered materials is of fundamental significance and of great interest for electronic and photonic applications. However, such orientation control is generally complicated and challenging with regard to inorganic and organic crystalline materials due to the occurrence of uncontrollable dislocations or defects. Achieving uniform lattice orientation in frustrated liquid-crystalline phases, like cubic blue phases, is a formidable task. Taming and tailoring the ordering of such soft, cubic lattices along predetermined or desired directions, and even imparting a prescribed pattern on lattice orientation, are more challenging, due to the entropy-domination attribute of soft matter. Herein, we disclose a facile way to realize designed micropatterning of a crystallographic direction of a soft, cubic liquid-crystal superstructure, exhibiting an alternate uniform and random orientation of the lattice crystallographic direction enabled by a photoalignment technique. Because of the rewritable trait of the photoalignment film, the pattern can be erased and rewritten on-demand by light. Such an oriented soft lattice sensitively responds to various external stimuli such as temperature, electric field, and light irradiation. Furthermore, advanced reflective photonic applications are achieved based on the patterned crystallographic orientation of the cubic blue phase, soft lattice.

Bent-core smectic liquid crystal (LC) phases (B phases) have been widely studied since their unusual polar and chiral properties were discovered in the 1990s. Relatively few studies have examined t...

"Equatorial" energy transfer: Orientation control of intramolecular energy transfer (EnT) is found in the donor–acceptor system shown, light absorbed by the "peripheral" anthracene is efficiently transferred to the porphyrin, but that by the "axial" anthracene subunits is not.

The orientation and crystallinity of Bi4Ti3O12 thin films grown by MOCVD on Pt-coated substrates can be arbitrarily controlled by varying the oxygen concentration and Bi/Ti composition ratio during growth, which in turn makes it possible to control the ferroelectric characteristics through their dependence on orientation. When the above-mentioned Bi4Ti3O12 thin films are combined with Bi2SiO5 insulator buffer layers to make Pt/Bi4Ti3O12/Pt/Bi2SiO5/Si MFMIS structures, the ferroelectricity of the Bi4Ti3O12 thin films is reflected in the C–V hysteresis, and applying a voltage of ±2 V reveals a memory window of about 2 V. Moreover, tests of the structures' data storage capability revealed almost no change after 24 hours. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(10): 49–58, 2001

Owing to a large diamagnetism, graphene flakes can respond and be aligned to magnetic field like a ferromagnetic material. Aligned graphene flakes exhibit emergent properties approaching single-layer graphene. Anisotropic optical properties also give rise to a magnetic writing board using graphene suspension and a bar magnet as a pen. This simple alignment technique opens up enormous applications of graphene.

The thallation-iodination of 3-carbonylindoles (4a-f) results in orientation control with substitution occurring at the 4-position (6a-f). Also described is the dithallation of N-methylpyrrole-2-carboxaldehyde (2).