A novel estimate for the line-to-ground capacitance that accurately predicts the pull-in instability parameters for narrow electrostatically actuated microbeams is proposed. Parameters in the proposed formula are obtained by least square fitting data from a fully converged numerical solution with the method of moments. For a narrow microbeam, it is shown that the new formula significantly impro...

In this study, analytical solution is presented to calculate the free vibration frequencies of nonuniform microbeams. Scale effects are modelled using modified couple stress theory and the microbeam is assumed to be thin while Poisson's ratio effects are also taken into account. Nonuniformity is presented by exponentially varying width among the microbeam while the thickness remains constant. R...

This paper presents an integration process of a novel tunable silver (Ag) deposit into MEMS surface micromachined bridge resonators. The mechanism of silver deposition is shown in Fig. 1. In this case, a blanket deposited Ag-doped chalcogenide glass film (Ge30 − Se70) serves as a solid electrolyte providing a medium for silver movement. Ag-ion migration in the electrolyte is induced by a DC vol...

Size-dependent behaviours of metal foam microbeams with three different porosity distribution models are studied in this paper. Based on the finite element model, a normal and shear deformation theory has been employed for first time to investigate their structural by using modified strain gradient considering effects variable material length scale parameter. The equations motion boundary condi...

New applications of laser microbeam irradiation to cell and developmental biology include a new instrument with a tunable wavelength (217- to 800-nanometer) laser microbeam and a wide range of energies and exposure durations (down to 25 X 10(-12) second). Laser microbeams can be used for microirradiation of selected nucleolar genetic regions and for laser microdissection of mitotic and cytoplas...

Charged-particle microbeams, developed to provide targeted irradiation of individual cells, and then of sub-cellular components, and then of 3-D tissues and now organisms, have been instrumental in challenging and changing long accepted paradigms of radiation action. However the potential of these valuable tools can be enhanced by integrating additional components with the direct ability to mea...

Radiotherapeutic doses for malignant gliomas are generally palliative because greater, supposedly curative doses would impart clinically unacceptable damage to nearby vital CNS tissues. To improve radiation treatment for human gliomas, we evaluated microbeam radiation therapy, which utilizes an array of parallel, microscopically thin (<100 microm) planar beams (microbeams) of synchrotron-genera...

Preclinical experiments are carried out with approximately 20-30 microm wide, approximately 10 mm high parallel microbeams of hard, broad-"white"-spectrum x rays (approximately 50-600 keV) to investigate microbeam radiation therapy (MRT) of brain tumors in infants for whom other kinds of radiotherapy are inadequate and/or unsafe. Novel physical microdosimetry (implemented with MOSFET chips in t...