No abstract

Artificial electronic skins (e-skins) comprise an integrated matrix of flexible devices arranged on a soft, reconfigurable surface. These sensors must perceive physical interaction spaces between external objects and robots or humans. Among various types of sensors, flexible magnetic sensors and the matrix configuration are preferable for such position sensing. However, sensor matrices must efficiently map the magnetic field with real-time encoding of the positions and motions of magnetic objects. This paper reports an ultrathin magnetic sensor matrix system comprising a 2 × 4 array of magnetoresistance sensors, a bootstrap organic shift register driving the sensor matrix, and organic signal amplifiers integrated within a single imperceptible platform. The system demonstrates high magnetic sensitivity owing to the use of organic amplifiers. Moreover, the shift register enabled real-time mapping of 2D magnetic field distribution.

A method is proposed for producing a significant reduction in the magnitude of the residual stress generated after cold drawing of a bar. It consists basically of a skin pass at the final stage of drawing and has a good levelling effect on the residual stress distribution as long as the final reduction falls within a specific range. The method was first proposed as a result of elastic-plastic finite element analyses using the ELFEN code developed by Rockfield Software Limited at the University of Wales, Swansea. The validity of the proposed method was verified by measuring the residual stress using the Sachs method.

increase in the numbers of dies and passes, which means an increase in the production cost. Therefore, there may be A new drawing die designed to reduce the residual cases which preclude adoption of the proposed method in stresses in bar after drawing is presented. The die the production line. design consists of two consecutive straight taperIt would be most convenient to design a new die geoportions, and the outlet portion has a very small die metry that will produce a similar effect in reducing residual angle. The marked beneficial effect of adding the stresses while permitting a normal final reduction to be given outlet portion was predicted by finite element to the bar as well as the final pass of the conventional modelling (FEM), and subsequently verified by drawing process. measuring the residual stresses in drawn bars.The solution can be arrived at by reviewing both the the The optimum range of the outlet die angle was skin pass method and the results of a study on the influence determined using FEM. The new design requires a of the 'R die', which is used in drawing soft materials such slightly longer die length than the conventional one, as aluminium or copper.8 The profile of an R die in the but it is short enough to be adopted in current longitudinal direction is a circular arc, and the reduction production lines.I&S/1505 per axial length gradually reduces toward the outlet side. If it is possible to give an ultralight reduction at the last stage