Flexible electronics utilizing single crystalline semiconductors typically require post-growth processes to assemble and incorporate the crystalline materials onto flexible substrates. Here we present a high-precision...Flexible electronics utilizing single crystalline semiconductors typically require post-growth processes to assemble and incorporate the crystalline materials onto flexible substrates. Here we present a high-precision transfer-printing method for vertical arrays of single crystalline semiconductor materials with widely varying aspect ratios and densities enabling the assembly of arrays on flexible substrates in a vertical fashion. Complementary fabrication processes for integrating transferred arrays into flexible devices are also presented and characterized. Robust contacts to transferred silicon wire arrays are demonstrated and shown to be stable under flexing stress down to bending radii of 20 mm. The fabricated devices exhibit a reversible tactile response enabling silicon based, nonpiezoelectric, and flexible tactile sensors. The presented system leads the way towards high-throughput, manufacturable, and scalable fabrication of flexible devices.展开更多
This paper presents a novel micro fabrication method based on the laminar characteristics of micro-scale flows. Therein the separator and etchant are alternatively arranged in micro channels to form multiple laminar s...This paper presents a novel micro fabrication method based on the laminar characteristics of micro-scale flows. Therein the separator and etchant are alternatively arranged in micro channels to form multiple laminar streams, and the etchant is located at the site where the reaction is supposed to occur. This new micro fabrication process can be used for the high aspect ratio etching inside a microchannel on glass substrates. Furthermore, the topography of microstructure patterned by this method can be controlled by changing the flow parameters of the separator and etchant. Experiments on the effects of flow parameters on the aspect ratio, side wall profile and etching rate were carried out on a glass substrate. The effect of flow rates on the etching rate and the micro topography was analyzed. In addition, experiments with dynamical changes of the flow rate ratio of the separator and etchant showed that the verticality of the side walls of microstructures can be significantly improved. The restricted flowing etching technique not only abates the isotropic effect in the traditional wet etching but also significantly reduces the dependence on expensive photolithographic equipment.展开更多
文摘Flexible electronics utilizing single crystalline semiconductors typically require post-growth processes to assemble and incorporate the crystalline materials onto flexible substrates. Here we present a high-precision transfer-printing method for vertical arrays of single crystalline semiconductor materials with widely varying aspect ratios and densities enabling the assembly of arrays on flexible substrates in a vertical fashion. Complementary fabrication processes for integrating transferred arrays into flexible devices are also presented and characterized. Robust contacts to transferred silicon wire arrays are demonstrated and shown to be stable under flexing stress down to bending radii of 20 mm. The fabricated devices exhibit a reversible tactile response enabling silicon based, nonpiezoelectric, and flexible tactile sensors. The presented system leads the way towards high-throughput, manufacturable, and scalable fabrication of flexible devices.
基金Project (No. 50705081) supported by the National Natural Science Foundation of China
文摘This paper presents a novel micro fabrication method based on the laminar characteristics of micro-scale flows. Therein the separator and etchant are alternatively arranged in micro channels to form multiple laminar streams, and the etchant is located at the site where the reaction is supposed to occur. This new micro fabrication process can be used for the high aspect ratio etching inside a microchannel on glass substrates. Furthermore, the topography of microstructure patterned by this method can be controlled by changing the flow parameters of the separator and etchant. Experiments on the effects of flow parameters on the aspect ratio, side wall profile and etching rate were carried out on a glass substrate. The effect of flow rates on the etching rate and the micro topography was analyzed. In addition, experiments with dynamical changes of the flow rate ratio of the separator and etchant showed that the verticality of the side walls of microstructures can be significantly improved. The restricted flowing etching technique not only abates the isotropic effect in the traditional wet etching but also significantly reduces the dependence on expensive photolithographic equipment.
