实现了一种利用双激光束(双光斑)的微型光热驱动的器(OTMA)。利用准分子激光微加工系统加工制作了膨胀臂宽为100μm、总长为750μm的非对称型OTMA;利用波长650nm的双激光束开展了OTMA的光热驱动实验研究,借助CCD显微视频运动测量系统,测定了光热偏转量与激光功率之间的关系曲线。实验结果表明,OTMA的光热偏转量与激光总功率之间近似成线性关系;当双光斑功率为4 mW时,OTMA获得的光热偏转量达到15.2μm,大于单光斑分别照射时的偏转量之和(13.1μm);同时,当双光斑照射与单光斑照射获得的光热偏转量相同时,双光斑的功率密度仅为单光斑的1/2甚至更小,从而可有效地避免单光斑照射时因局部温升过高而导致OTMA烧结损坏,延长了器件的工作寿命。本文的OTMA结构简单,易于加工,偏转量大,易于操作,并且可以实现无线远距离控制;可望在微纳米技术及微型光机电系统等领域获得广泛应用。
This paper proposes a novel method of optothermal microactuating based on dual laser beams (spots). An optothermal microaetuator (OTMA) with a 100 μm-width expansion arm and 750 μm- length is designed and manufactured by using an excimer laser micromachining system. Experiments are carried out on the OTMA using dual laser beams with 650 nm wavelength,which are monitored by the CCD microscopic system. The results show that the deflection-power curves exhibit approximate linear relationship between the optothermal deflection of OTMA and the power of laser spots. Furthermore, when the total power is 4 roW, the optothermal defletion caused by dual laser spots reaches 15.2 μm, larger than the sum (13.1 μm) of those individually caused by the left and right laser spots. Meanwhile, as the power density of dual spots is only half of that of single spot when obtaining the same deflection, this method can effectively avoid burning-out and damage of OTMA, and thus OTMA's working lifetime can be significantly extended. The method of optothermal microactuating is of the advantages of simple structure, easy fabrication, large displacement, convenience for operation, and enables wireless and remote control. It has high potential of being widely applied in the fields of micro/nano-teehnology and microopto- electro-mechanical systems.