Preparation Of Multi-tip Array On Flexible Substrates For Large-scale Micro/nanofabrication

As a fundamental backbone for nanotechnology, micro/nanofabrication are served for achieving high-performance micro/nano structures and devices. With an increasing demand for scientific and industrial applications, the existing fabrication methods cannot satisfy the requirement for the development, and it is of significance to explore new fabrication technology methods. Compared with single-tip mode for SPM-based fabrication, parallel multi-tip mode provides an effective way for micro/nanofabrication with large scale and high efficiency. The preparation of multiple probes plays a key role for updating SPM-based fabrication. Towards enlarging the fabrication range and improving the efficiency, a method for the preparation of multi-tip array on the flexible substrates is proposed in this paper. The main conclusions and innovative points could be summarized as below.(1) A preparation method of multi-tip array on flexible substrate for large-scale micro/nanofabrication was proposed. The microspheres were positioned on the designed indent array produced on the wax substrate. The flexible substrate was filled between the multi-tip plate and the microspheres. Patterned multi-tip arrays were fabricated on the flexible substrates.(2) Based on the finite element analysis carried out by ABAQUS 6.11, a theoretical model for selecting a suitable hyperelastic material for the flexible substrates of the multi-tip array was presented. The constitutive relation of the hyperelastic material was quantified by the Yeoh model. Considering the two extreme criteria based on the requirement in actual contact, the hyperelastic material with the first coefficient of Yeoh constitutive relation C10 ranging from 0.5 to 17 can be selected as the suitable substrate for the tip arrays.(3) The fabrication by the tip arrays were realized, and the above theoretical prediction was verified. Processing effect of the multi-tip arrays with different flexible substrates was studied. Comparative experiments were conducted by different multi-tip arrays with flexible substrates and without flexible substrates. Based on the experimental results, the multi-tip array with nitrile rubber or fluorine rubber as flexible substrates can obviously compensate the height difference resulting from microsphere size, where the first coefficient C10 of these two rubbers is in the range from 0.5 to 17. It is in conformity with the results of finite element analysis.A low-cost and easy-operating preparation method of multi-tip array was provided and the theoretical basis for selecting suitable flexible substrates for the multi-tip array was presented in this paper. The study can not only contribute to promoting the application of the friction-induced nanofabrication, but also provide instructions for developing the low-cost and large-scale fabrication.