PDMS梯度光栅结构制备技术研究

The Study of PDMS Grating Structure Gradient Preparation Techniques

由于传统方法制作的梯度光栅,工艺条件苛刻,制作过程复杂,难以控制,制作成本高,周期较长,提出了一种成本低、工艺简单、可大量制备梯度光栅的工艺方法,采用基于刚性薄膜/柔性衬底的自组装工艺和氧等离子体(Plasma)的方法制备了微米尺度的梯度光栅,利用Plasma时间的可控性和聚二甲基硅氧烷(PDMS)优异的弹性制得所需要尺寸的光栅。首先在聚乙烯对苯二酸脂(PET)薄膜上旋涂一层PDMS薄膜,待PDMS薄膜固化后将双层薄膜弯曲并用Plasma处理,在其表面生成一层刚性氧化层,借助柔性的PET对刚性层施加均匀应力,当应力超过临界值时,在PDMS基底上自组装形成光栅褶皱结构。由于弯曲时预应力的变化,所以在PDMS薄膜上会形成周期和高度呈阶梯状的的光栅褶皱,也就是梯度光栅。采用可见光作为梯度光栅的性能测试光源,选用一级衍射光作为检测对象,从图谱中可以看出以PDMS为基底制备的光栅具有很好的衍射效应,并可实现很好的分光效果。实验表明:梯度光栅具有明显的衍射现象,并且衍射角变化显著,可广泛用于应力测量。这种方法制备的柔性梯度光栅也可以作为微型应变装置来检测应力的变化,未来有望用于微型光谱仪、扫描仪、光通讯等领域中。

Because traditional method for tunable grating fabrication has harsh process condition, complex fabrication process, high costs and long cycle. Proposed a low-cost, simple process, can be prepared in large quantities gradient grating process method, based on self-assembly process using the rigid film/flexible substrate and oxygen plasma method prepared a micron scale gradient grating. Use of plasma free time controllability and excellent elastic of PDMS obtained the desired grating. First, polyethylene terephthalate （PET） was spin-coated layer of polydimethylsiloxane （PDMS） film on the thin film, two-layer film to be cured PDMS film after bending and treated with an oxygen plasma （plasma）, in generating a rigid surface oxide layer,With flexible PET rigid layer applied uniform stress, when the stress exceeds the critical value, the PDMS substrate to form a self-assembled structure grating fold. Due to changes in prestressed bending, so the PDMS film formation period and height of the grating stepped fold, which is graded grating. Using visible light as the performance test light source for graded grating and selecting first-order diffracted as the detection target. The authors can see the grating has a good diffraction effects and achieves good spectral effect. Experiments show that graded grating has obvious diffraction grating, and the diffraction angle varies significantly, and can be widely used for stress measurement, the flexible gradient grating prepared by this method can also be used to detect changes in the stress strain as a miniature device, the future is expected for miniature spectrometer, scanners, optical communications and other fields.