Flip-chip distributed MEMS transmission lines (DMTLs) for biosensing applications

Design and characterization of a flip-chip distributed MEMS transmission line (DMTL) are presented. The concept of using this DMTL as a biosensor is then introduced. Radio frequency experiments on the DMTL loaded with biosamples have been conducted using the most accessible materials, namely, deionized water and aqueous solutions of salts. Results show that the reflection coefficient (S11) of the solution-loaded DMTL is very sensitive to the salt concentration of the solution in the low-frequency ranges of 10 MHz-1 GHz and 3-4.5 GHz. At high frequencies, the relative dielectric constant of the biosample can also be quantitatively determined from the impedance of the DMTL

Analysis of microsprings for calculating the force produced by microactuators

We present models of two types of microsprings namely box-spring and zig-zag spring that can be used to measure the force generated by microactuators. The spring constant for both springs is calculated by FEM using ANSYS software. In these models, the effects of short beams that act as connectors in the spring structures are considered and analyzed by changing their width. Also, from the results, we find that the box spring appears more balanced than the zig-zag spring when the force is applied in the single central direction. A series of SDAs with box spring have been fabricated and forces ofthose SDAs have been calculated

Optical driven electromechanical transistor based on tunneling effect

A new electromechanical transistor based on an optical driven vibrational ring structure has been postulated. In the device, optical power excites the ring structure to vibrate, which acts as the shuttle transporting electrons from one electrode to the other forming the transistor. The electrical current of the transistor is adjusted by the optical power. Coupled opto-electro-mechanical simulation has been performed. It is shown from the dynamic analysis that the stable working range of the transistor is much wider than that of the optical wave inside the cavity, i.e., the optical resonance enters nonperiodic states while the mechanical vibration of the ring is still periodic

Strain magnitude and direction effect on the energy band structure of hexagonal and orthorhombic monolayer MoS2

We report changes of the band structure of hexagonal and orthorhombic cells of the monolayer molybdenum disulfide (MoS2) subject to various magnitude and direction of the mechanical strains based on the first principle method. The conduction band minimum (CBM) of this two-dimensional (2D) material has been calculated to establish the relation with both the magnitude and direction of the strains. It is found that the CBM at Γ point of the hexagonal cell decreases in a slight concave shape for the tensile strain, and a convex shape for the compressive strain. For the orthorhombic cell, we demonstrate that the effect is almost independent on the direction of the applied tensile strain. However, there is a strong directional dependence for compressive strain

Chaos control of parametric driven Duffing oscillators

Duffing resonators are typical dynamic systems, which can exhibit chaotic oscillations, subject to certain driving conditions. Chaotic oscillations of resonating systems with negative and positive spring constants are identified to investigate in this paper. Parametric driver imposed on these two systems affects nonlinear behaviours, which has been theoretically analyzed with regard to variation of driving parameters (frequency, amplitude). Systematic calculations have been performed for these two systems driven by parametric pumps to unveil the controllability of chaos

Piezophototronic Effect Enhanced Perovskite Solar Cell Based on P(VDF‐TrFE)

As a candidate for next-generation solar devices, perovskite solar cells are increasingly being studied for their rapid increased power conversion efficiency (PCE). One of the possible routes to further increase PCE is the introduction of polarization in the absorption layer which functions as a method for increasing the built-in potential and reducing the interface barrier, leading to much improved carrier separation and extraction. This technique uses the principle of the piezophototronic effect utilized for obtaining enhanced optoelectronic performances. Herein, to introduce internal polarization while maintaining optical absorption performance of the perovskite, organic–inorganic hybrid perovskite composite film solar cells are fabricated by doping polarized polyvinylidenefluoride-co-trifluoroethylene (P(VDF-TrFE)) into the perovskite. The composite film is polarized with an external potential, subsequently inducing the piezophototronic effect to enhance the performances of perovskite solar cells. Experimental results show that this simple polarization method has effectively improved several key characteristics of the solar cell. The PCE has reached up to 22.1%, the short-circuit current (Jsc) increases to 24.2 mA cm−2, and the open-circuit voltage (Voc) increases to 1.18 V