Department of Chemical Engineering , Auburn University , Auburn , Alabama 36849 , United States.
Department of Chemical and Biomolecular Engineering , Clemson University , Clemson , South Carolina 29634 , United States.
ACS Appl Mater Interfaces. 2018 Jul 18;10(28):24116-24123. doi: 10.1021/acsami.8b04985. Epub 2018 Jul 9.
Microelectromechanical systems (MEMS) have become a ubiquitous part of a multitude of industries including transportation, communication, medical, and consumer products. The majority of commercial MEMS devices are produced from silicon using energy-intensive and harsh chemical processing. We report that actuatable standard MEMS devices such as cantilever beam arrays, doubly clamped beams, residual strain testers, and mechanical strength testers can be produced via low-temperature fabrication of shear-aligned cellulose nanocrystal (CNC) films. The devices had feature sizes as small as 6 μm and anisotropic mechanical properties. For 4 μm thick doubly clamped beams with the CNC aligned parallel to the devices' long axes, the Young's moduli averaged 51 GPa and the fracture strength averaged 1.1 GPa. These mechanical properties are within one-third of typical values for polysilicon devices. This new paradigm of producing MEMS devices from CNC extracted from waste biomass provides the simplicity and tunability of fluid-phase processing while enabling anisotropic mechanical properties on the order of those obtained in standard silicon MEMS.
微机电系统（MEMS）已经成为包括交通、通信、医疗和消费产品在内的众多行业中无处不在的一部分。大多数商业 MEMS 设备都是使用能源密集型和苛刻的化学处理工艺从硅中生产的。我们报告说，可动标准 MEMS 器件，如悬臂梁阵列、双夹梁、残余应变测试仪和机械强度测试仪，可以通过低温制造剪切对齐的纤维素纳米晶体（CNC）薄膜来生产。这些器件的特征尺寸小至 6μm，具有各向异性的机械性能。对于厚度为 4μm 的双夹梁，其中 CNC 与器件的长轴平行排列，杨氏模量平均为 51GPa，断裂强度平均为 1.1GPa。这些机械性能在典型的多晶硅器件值的三分之一范围内。这种从废生物质中提取 CNC 来生产 MEMS 器件的新范例提供了流体相处理的简单性和可调节性，同时使机械性能具有各向异性，达到了标准硅 MEMS 中获得的性能。
