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A coordinate measuring machine (CMM) is widely used for surface measurement during milling and grinding of workpieces. However, the measurement uncertainty increases with the surface slope for highly steep freeform surfaces. In addition, local features sometimes exist on the surface out of the accessible space of the CMM. This study presents a coordinate measurement method based on stitching multiple subpatches. The complex freeform surface of a large slope is first divided into subpatches which are individually tilted and measured with smaller uncertainty due to reduced slopes. A global stitching algorithm is then proposed to compensate the motion error and stitch all the subpatches together simultaneously, based on configuration optimization to minimize the overlap inconsistency. The coordinate stitching measurement method is first validated through simulation, which shows that the motion error of the order of 0.05°/0.5 mm is tolerable for a highly steep surface. It is then experimentally verified using the stitching measurement of an optical spherical surface and a steep freeform surface. An ordinary multi-axis adjustment stage is suitable for subpatch repositioning because the stitching algorithm compensates the motion error to a level lower than the CMM uncertainty. [ABSTRACT FROM AUTHOR]

Advances in flexible electronic and optoelectronic devices have caused higher requirements for fabricating high-performance and low cost flexible transparent conductive electrodes (TCEs). Copper nanowires (Cu NWs) possess excellent electrical and optical properties, but the large contact resistance and poor stability limit their practical application in optoelectronic devices. In this work, we report a robust, convenient and environment-friendly method to assemble copper nanowires/reduced graphene oxide (Cu NWs/rGO) TCEs with enhanced conductivity, flexibility and stability at room temperature. The NaBH4 treatment was used to remove the organics and oxides on the surface of Cu NWs, and the graphene oxide (GO) capping layer was also effectively reduced at the same time. The best Cu NWs/rGO composite TCEs show a good optical-electrical performance with a sheet resistance of ∼50 Ω/sq and transmittance of 83% as well as superior mechanical flexibility. The oxidation resistance of Cu NWs in normal environment and even at a relatively high temperature has also been greatly improved. Additionally, the Cu NWs/rGO TCEs based heaters presented high saturation temperature and rapid response time under a low voltage. The high-performance composite Cu NWs TCEs with good stability are expected to be applied in various types of flexible optoelectronic devices. [ABSTRACT FROM AUTHOR]