Nanostructured 2D cellular materials in silicon by sidewall transfer lithography NEMS

Abstract

Sidewall transfer lithography (STL) is demonstrated as a method for parallel fabrication of 2D nanostructured cellular solids in single-crystal silicon. The linear mechanical properties of four lattices (perfect and defected diamond; singly and doubly periodic honeycomb) with low effective Young's moduli and effective Poisson's ratio ranging from positive to negative are modelled using analytic theory and the matrix stiffness method with an emphasis on boundary effects. The lattices are fabricated with a minimum feature size of 100 nm and an aspect ratio of 40 : 1 using single-and double-level STL and deep reactive ion etching of bonded silicon-oninsulator. Nanoelectromechanical systems (NEMS) containing cellular materials are used to demonstrate stretching, bending and brittle fracture. Predicted edge effects are observed, theoretical values of Poisson's ratio are verified and failure patterns are described.

Flexibility-based stress-driven nonlocal frame element: formulation and applications

“…To narrow the research gap in the area of nonlocal finite element models, the development of a rational nonlocal frame model with computational efficiency is sought. As mentioned by Numanoglu and Civalek [75] and Russillo et al [76], nano-sized skeleton structures have found a wide spectrum of novel applications in nanoscience and nanotechnology: auxetic metamaterials [9][10][11], carbon nanotube networks [12][13], cellular nanostructures [77], and electro-thermal actuator bent-beams [78] [79] to develop their nonlocal frame models. Therefore, paradoxical and inconsistent responses can possibly be obtained with these nonlocal frame models.…”

Suppressing Crystallinity by Nanoconfining Polymers Using Initiated Chemical Vapor Deposition

“…Nanostructures have drawn much attention due to their applications in a variety of fields, like microelectronics, nanoelectromechanical systems devices, , energy harvesting and storage systems, , latent heat transfer, , self-cleaning, , biomedical devices, , and drug delivery. , With the wide range of applications, different methods have been developed to create these nanostructures, including aerogel or sol–gel deposition, , nanolithography, electrochemical deposition, physical/chemical vapor deposition, , and atomic layer deposition . As a way to further utilize these nanostructures, a lot of effort has been made to integrate them with different materials, particularly polymers, to form nanocomposites .…”

Improved optical imaging of high aspect ratio nanostructures using dark-field microscopy

“…Processes such as sidewall transfer lithography (STL) allow parallel fabrication of restricted feature sets. This method combines repeated STL (originally developed for field-effect transistor fabrication [3,4] and subsequently used for other features such as nanowires [5]) with standard MEMS processing [6,7] to form more general structures [8,9]. However, the need for metrology remains.…”