Kurek Maksymilian, Larsen Frederik K, Larsen Peter E, Schmid Silvan, Boisen Anja, Keller Stephan S
Department of Micro- and Nanotechnology, Technical University of Denmark, Kgs. Lyngby 2800, Denmark.
Institute of Sensor and Actuator Systems, TU Wien, Vienna 1040, Austria.
Sensors (Basel). 2016 Jul 15;16(7):1097. doi: 10.3390/s16071097.
Micro- and nanomechanical string resonators, which essentially are highly stressed bridges, are of particular interest for micro- and nanomechanical sensing because they exhibit resonant behavior with exceptionally high quality factors. Here, we fabricated and characterized nanomechanical pyrolytic carbon resonators (strings and cantilevers) obtained through pyrolysis of photoresist precursors. The developed fabrication process consists of only three processing steps: photolithography, dry etching and pyrolysis. Two different fabrication strategies with two different photoresists, namely SU-8 2005 (negative) and AZ 5214e (positive), were compared. The resonant behavior of the pyrolytic resonators was characterized at room temperature and in high vacuum using a laser Doppler vibrometer. The experimental data was used to estimate the Young's modulus of pyrolytic carbon and the tensile stress in the string resonators. The Young's moduli were calculated to be 74 ± 8 GPa with SU-8 and 115 ± 8 GPa with AZ 5214e as the precursor. The tensile stress in the string resonators was 33 ± 7 MPa with AZ 5214e as the precursor. The string resonators displayed maximal quality factor values of up to 3000 for 525-µm-long structures.
微纳机械弦谐振器本质上是高应力桥，因其具有极高品质因数的谐振行为，在微纳机械传感领域备受关注。在此，我们制备并表征了通过光刻胶前驱体热解得到的纳米机械热解碳谐振器（弦和悬臂梁）。所开发的制造工艺仅包括三个加工步骤：光刻、干法蚀刻和热解。比较了使用两种不同光刻胶（即SU - 8 2005（负性）和AZ 5214e（正性））的两种不同制造策略。使用激光多普勒振动计在室温及高真空环境下对热解谐振器的谐振行为进行了表征。实验数据用于估计热解碳的杨氏模量和弦谐振器中的拉应力。以前驱体SU - 8计算的杨氏模量为74±8 GPa，以前驱体AZ 5214e计算的杨氏模量为115±8 GPa。以前驱体AZ 5214e的弦谐振器中的拉应力为33±7 MPa。对于525 µm长的结构，弦谐振器显示出高达3000的最大品质因数。
