Electrothermal bimorph-based scanning micromirrors typically employ standard silicon dioxide(SiO_(2))as the electrothermal isolation material.However,due to the brittle nature of SiO_(2),such micromirrors may be incap...Electrothermal bimorph-based scanning micromirrors typically employ standard silicon dioxide(SiO_(2))as the electrothermal isolation material.However,due to the brittle nature of SiO_(2),such micromirrors may be incapable to survive even slight collisions,which greatly limits their application range.To improve the robustness of electrothermal micromirrors,a polymer material is incorporated and partially replaces SiO_(2) as the electrothermal isolation and anchor material.In particular,photosensitive polyimide(PSPI)is used,which also simplifies the fabrication process.Here,PSPIbased electrothermal micromirrors have been designed,fabricated,and tested.The PSPI-type micromirrors achieved an optical scan angle of±19.6°and a vertical displacement of 370μm at only 4 Vdc.With a mirror aperture size of 1 mm×1 mm,the PSPI-type micromirrors survived over 200 g accelerations from either vertical or lateral directions in impact experiments.In the drop test,the PSPI-type micromirrors survived falls to a hard floor from heights up to 21 cm.In the standard frequency sweeping vibration test,the PSPI-type micromirrors survived 21 g and 29 g acceleration in the vertical and lateral vibrations,respectively.In all these tests,the PSPI-type micromirrors demonstrated at least 4 times better robustness than SiO_(2)-type micromirrors fabricated in the same batch.展开更多
基金The authors would like to acknowledge the help of the staff from the Center of Nanofabrication,Tsinghua University for device fabrication.
文摘Electrothermal bimorph-based scanning micromirrors typically employ standard silicon dioxide(SiO_(2))as the electrothermal isolation material.However,due to the brittle nature of SiO_(2),such micromirrors may be incapable to survive even slight collisions,which greatly limits their application range.To improve the robustness of electrothermal micromirrors,a polymer material is incorporated and partially replaces SiO_(2) as the electrothermal isolation and anchor material.In particular,photosensitive polyimide(PSPI)is used,which also simplifies the fabrication process.Here,PSPIbased electrothermal micromirrors have been designed,fabricated,and tested.The PSPI-type micromirrors achieved an optical scan angle of±19.6°and a vertical displacement of 370μm at only 4 Vdc.With a mirror aperture size of 1 mm×1 mm,the PSPI-type micromirrors survived over 200 g accelerations from either vertical or lateral directions in impact experiments.In the drop test,the PSPI-type micromirrors survived falls to a hard floor from heights up to 21 cm.In the standard frequency sweeping vibration test,the PSPI-type micromirrors survived 21 g and 29 g acceleration in the vertical and lateral vibrations,respectively.In all these tests,the PSPI-type micromirrors demonstrated at least 4 times better robustness than SiO_(2)-type micromirrors fabricated in the same batch.
