Wireless magnetic-based control of paramagnetic microparticles

This work investigates modeling and control of microparticles that could be guided inside the human body using external magnetic fields. Proposed areas of applications for these microparticles include but not limited to minimally invasive surgeries, diagnosis and sensing. The problem is formulated by modeling a magnetic prototype system which has been developed for the purpose of wireless motion control of microparticles. A control system is devised based on the way-point approach to control the navigation of the microparticles in a fluid. In addition, a path planning procedure based on a combination of the potential field and the A* approaches is investigated in order to control the motion of the microparticles in the presence of static and dynamic obstacles. The experimental verification is conducted on a magnetic system designed for manipulation of microparticles. The experimental results demonstrates the motion control of microparticles with maximum steady state position tracking error of 8.6 μm within a 2.4 mm×1.8 mm workspace

Wireless magnetic-based control of paramagnetic microparticles

This work investigates modeling and control of microparticles that could be guided inside the human body using external magnetic fields. Proposed areas of applications for these microparticles include but not limited to minimally invasive surgeries, diagnosis and sensing. The problem is formulated by modeling a magnetic prototype system which has been developed for the purpose of wireless motion control of microparticles. A control system is devised based on the waypoint approach to control the navigation of the microparticles in a fluid. In addition, a path planning procedure based on a combination of the potential field and the A∗ approaches is investigated in order to control the motion of the microparticles in the presence of static and dynamic obstacles. The experimental verification is conducted on a magnetic system designed for manipulation of microparticles. The experimental results demonstrates the motion control of microparticles with maximum steady state position tracking error of 8.6 μm within a 2.4 mm×1.8 mm workspace

Can augmented force feedback facilitate virtual target acquisition tasks?

This study investigates facilitation of a manual target acquisition task by the application of appropriate force feedback through the control device (e.g., mouse, joystick, trackball). Typical manual movements with these devices were measured, and models of such movements were used to predict an intended target location from an initial portion of a trace. Preferred shapes and sizes for feedback force functions to be applied were empirically determined by collecting preference ratings and measuring task completion times. The general experimental task that is typical for an office situation, but findings appear generalizable to some medical and surgical situations (e.g. laparoscopy, catheterization) where a certain target has to be reached whose precise location may be known or unknown

A comparative study of the effects of nontoxic chloride treatments on CdTe solar cell microstructure and stoichiometry

This work presents the first systematic comparison of the effects of a range of chlorides (CdCl2, MgCl2, NaCl, and NH4Cl) on the microstructure and chemical composition of CdTe/CdS/ZnO/SnO2 solar cells, providing valuable insight to the ubiquitous Cl-activation process. Using X-ray diffraction, it is shown that CdCl2 induces the greatest extent of recrystallization (standard deviation of texture coefficients, s, reduces from 0.93 for as-grown CdTe to 0.43) and minimizing stress (from 178 MPa for as-grown material to zero). MgCl2 treatment also yields significant randomization of the CdTe texture (s = 0.55) but NaCl treatment does not (s = 1.10). A strong correlation between the extent of metallurgical changes induced by the chloride treatment (and consequently, device efficiency) and the dissociation energy of the cationCl bond is shown, thereby accounting for the ineffectiveness of NaCl (bond energy = 4.3 eV). From this, a mechanism for Cl activation is postulated. By X-ray photoelectron spectroscopy it is also shown that the Te/Cd ratio at the back surface, and the Cl content at the CdTe–CdS interface, are both higher following CdCl2- and MgCl2 treatments (Te/Cd = 1.3–1.4, and 1–2 at% Cl) than following NaCl treatment (Te/Cd = 1.1, and 0 at% Cl)