Abstract This paper presents a theory for predicting the wavelength and ampli-tude of the wrinkles that form in a membrane in pure shear. Predictions from this theory are compared to experimental measurements and a fi-nite element simulation and are found to be very accurate.

Since the introduction of the iPhone and Wii gaming console in 2007 the market for mobile sensor appli-cations has exploded. A continuous effort is made to make these sensors smaller, better and cheaper. This allowed for new applications that caused the market to grow exponentially in recent years. Pressure sensors have recently found implementation in the mobile sensor market, however they require lots of fabrication steps making them relatively expensive. Due to its exceptional properties, graphene can be used as both an electrical and mechanical element reducing the amount of fabrication steps needed to build a pressure sensor. Using this principle, concepts for an absolute (atmospheric) pressure sensor and pressure difference (gage) sensor were developed. Novel analytical solutions were developed and compared to existing measure-ments of similar devices or to numerical simulations. It is found that these devices will not only be smaller and cheaper, but also have a larger bandwidth and less sensitivity to mechanical disturbances. The thermal noise of these devices is orders of magnitude lower than similar silicon based devices, therefore it is expected that graphene based sensors will meet the demands on accuracy, resolution and signal-to-noise ratio of cur-rent high-precision pressure sensors. It is concluded that graphene based resonant pressure sensors have the potential to meet the future mobile market demands.

The co-rotational (CR) technique is a kinematics description, which can be traced back to work by Wempner1. Up to now, most of the research efforts on a co-rotational framework have been focused on beams and shells, but there are also some investigations extending the CR procedures to other continuum elements. A recent review of the state of the art of CR formulation is given by Felippa and Hauge2. The concept of an element-independent co-rotational (EICR) formulation has been proposed by Rankin and coworkers3, with its most significant feature that extraction and integration of rigid body motion can be done in a module called CR filter, independent of linear element calculation. A unified approach to the finite element method in a co-rotational (CR) framework is proposed. A commonly applicable filter was developed according to the framework, with which many nonlinear CR elements can be easily developed by integrating the filter with corresponding linear elements. The main points of the developed procedure is a generality in basic formulation, and an algorithm based on nodal contributions. The CR filter is formulated as a strict minimization problem, which is solved by rapidly converging Newton iterations. Three continuum elements were developed in this framework4. Numerical examples with large displacements were tested with the CR elements developed in this way. The test results and the performance of the elements are analyzed, and conclusions are drawn, proving the unified approach to be promising, but also indicating the main problems with the CR framework.

In this paper, numerical methods for wrinkle prediction of thin membrane were studied by finite element analysis. Techniques using membrane and shell elements were applied for triangular membrane. In case of membrane element method, the wrinkling was accounted for by the wrinkle algorithm

ABSTRACT There has been an increasing interest in the applications of thin membrane in space application, flexible electronic display, manufacturing of glass displays and growth of film on materials at elevated temperatures. Because of the negligible bending stiffness of thin membranes, membranes

ABSTRACT Motile cells explore their surrounding milieu by extending thin dynamic protrusions, or filopodia. The growth of filopodia is driven by actin filament bundles that polymerize underneath the cell membrane. We compute the mechanical and dynamical features of the protrusion growth process

Thin solar sail membranes of very large span are being envisioned for near-term space missions. One major design issue that is inherent to these very flexible structures is the formation of wrinkling patterns. Structural wrinkles may deteriorate a solar sail’s performance and, in certain cases

-based finite element (FE) model of a thin strip of Kapton HN material with a monolithic PZT bimorph bonded near a boundary is developed in a MatLab environment and verified experimentally. The membrane strip under tension is modeled as a beam under axial load. In doing so, the FE model is able to capture

Since protein patterning on 2D surfaces has emerged as an important tool in cell biology, the development of easy patterning methods has gained importance in biology labs. In this paper we present a simple, rapid and reliable technique to fabricate thin layers of UV curable polymer with through

Membrane structures have a wide field of application in modern engineering. It ranges from aerospace to civil engineering, and even in bioengineering to analyse cell structures. The advantage of membranes is their low weight-to-area ratio which is especially exploited for kites. In this thesis