Inkjet fabrication processes for large area nanostructured strain sensors

该项目的目标是开发一种基于喷墨微图案化纳米结构复合材料的近净形状制造工艺。它满足了加拿大对替代、低成本、有竞争力和绿色制造方法的需求。该技术将使高性能传感器的制造成本低廉，用于桥梁、混凝土结构、管道或其他关键基础设施的结构健康监测(SHM)。目前关键基础设施缺乏负担得起的SHM与GDP损失1%有关。喷墨微图案化通过按需滴加沉积多种材料(聚合物、溶剂、包含纳米线和纳米管的功能复合材料等)来制造微器件。以“油墨”的形式在刚性、柔性、粗糙、光滑和3-D基板上进行非接触图案制作，能够以低成本生产非常大面积的器件。该工艺精度高、分辨率较高(10-100微米)、速度快。这也是绿色制造的一个例子，因为这个过程消耗的材料很少，产生的废物也很少。将开发新的工艺，其中喷墨微图案化与创新的流体动力学技术相结合，以控制印刷纳米管和纳米线的对准。它们的排列最大化了碳纳米管的本征巨压阻效应和半导体纳米线的巨压电效应。这项技术将使新型应变传感设备的制造成为可能，其灵敏度比传统应变计高两个数量级。此外，印刷结构的零应力电阻较高，导致功耗较低，且受引线中电阻的影响较小。碳纳米管和金属氧化物纳米线的机械和化学稳定性将提高器件的长期稳定性。除了SHM，潜在的制造技术还将作为探索许多其他传感应用的平台。

This project targets the development of a near-net-shape fabrication process based on inkjet micropatterning of nanostructured composites. It addresses Canada's need for alternative low-cost competitive and green manufacturing methods. The technology will enable the inexpensive manufacturing of high performance sensors for structural health monitoring (SHM) of bridges, concrete structures, pipelines or other critical infrastructure. The current lack of affordable SHM of critical infrastructure has been linked to a loss in GDP of 1%. Inkjet micropatterning enables the fabrication of microdevices by drop-on-demand deposition of a wide variety of materials (polymers, solvents, functional composites containing nanowires and nanotubes, etc.) in the form of "inks" for non-contact patterning onto rigid, flexible, rough, smooth, and 3-D substrates and is capable of producing very large area devices at low-cost. The process is accurate, relatively high resolution (10-100µm), and high speed. It is also an example of green manufacturing since the process consumes very little material and produces little waste. New processes will be developed, where inkjet micropatterning is used in conjunction with an innovative hydrodynamic technique for controlled alignment of printed nanotubes and nanowires. Their alignment maximizes the intrinsic giant piezoresistive effect in carbon nanotubes and the giant piezoelectric effect in semiconductor nanowires. This technique will enable the manufacturing of novel strain sensing devices with sensitivities two orders of magnitude greater than conventional strain gauges. In addition, the higher zero-stress resistance of the printed structures results in lower power consumption and less influence from the resistance in the lead wires. The mechanical and chemical stability of carbon nanotubes and metal oxide nanowires will improve the long-term stability of the devices. In addition to SHM, the underlying fabrication technology will serve as a platform for exploring many other sensing applications.