Assembly of charged aerosols on non-conducting substrates via ion-assisted aerosol lithography (IAAL)

The development of ion-assisted aerosol lithography (IAAL) has enabled fabrication of complex three-dimensional nanoparticle (NP) structures on conducting substrates. In this work, the applicability of the IAAL technique was investigated on non-conducting substrates. The NP structure growth process on a non-conducting substrate was found to self-terminate and the structures subsequently repel incoming charged NPs and scatter them away. Electric field calculations supported the experimental findings and confirmed that the electric field distortions owing to charge build-up within the structures prevented additional NP deposition thereon. To regulate the charge build-up without compromising the number of NPs available for assembly, a corona discharger and an ion trap were implemented. By varying the number of ions available in the assembly process, an optimum level of ion injection was found that allowed for a prolonged (>120 min) assembly of NP structures on non-conducting substrates without the unwanted scattering of NPs.