Electronically Tunable Minimum Component Biquadratic Filters for Interface Circuits

In this paper, two new electronically tunable filter configurations are proposed. The proposed filters operate current-mode (CM), voltage-mode (VM), transimpedance-mode (TIM) and transadmittance-mode (TAM). The first configuration realizes second-order VM band-pass and TAM high-pass filter characteristics from the same configuration. The second one realizes second-order TIM band-pass and CM low-pass filter characteristics from the same configuration. They also use minimum number of electronic components (two capacitors and one active component namely;current controlled current difference transconductance amplifier). The workability of the proposed structures has been demonstrated by simulation results.

Interlayer engineering in 3D graphene skeleton realizing tunable electronic properties at a highly controllable level for piezoresistive sensors

Three-dimensional(3D)graphene is a promising active component for various engineering fields,but its performance is limited by the hidebound electrical conductivity levels and hindered electrical transport.Here we present a novel approach based on interlayer engineering,in which graphene oxide(GO)nanosheets are covalently functionalized with varied molecular lengths of diamine molecules.This has led to the creation of an unprecedented class of 3D graphene with highly adjustable electronic properties.Theoretical calculations and experimental results demonstrate that ethylenediamine,with its small diameter acting as a molecular bridge for facilitating electron transport,has the potential to significantly improve the electrical conductivity of 3D graphene.In contrast,butylene diamine,with its larger diameter,has a reverse effect due to the enlarged spacing of the graphene interlayers,resulting in conductive degradation.More importantly,the moderate conductive level of 3D graphene can be achieved by combining the interlayer spacing expansion effect and theπ-electronic donor ability of aromatic amines.The resulting 3D graphene exhibits highly tunable electronic properties,which can be easily adjusted in a wide range of 2.56-6.61 S·cm^(-1)compared to pristine GO foam(4.20 S·cm^(-1)).This opens up new possibilities for its use as an active material in a piezoresistive sensor,as it offers remarkable monitoring abilities.

Facile intercalation of alkali ions in WO_(3)for modulated electronic and optical properties:Implications for artificial synapses and chromogenic application

Tungsten oxides(WO_(3))are widely recognized as multifunctional systems owing to the existence of rich polymorphs.These diverse phases exhibit distinct octahedra-tilting patterns,generating substantial tunnels that are ideally suited for iontronics.However,a quantitative comprehension regarding the impact of distinct phases on the kinetics of intercalated conducting ions remains lacking.Herein,we employ first-principles calculations to explore the spatial and orientational correlations of ion transport inγ-and h-WO_(3),shedding light on the relationship between diffusion barriers and the size of the conducting ions.Our findings reveal that different types and concentrations of alkali-metals induce distinct and continuous lattice distortions in WO_(3)polymorphs.Specifically,γ-WO_(3)is more appropriate to accommodate Li+ions,exhibiting a diffusion barrier and coefficient of 0.25 eV and 9.31×10^(-8)cm^(2)s^(-1),respectively.Conversely,h-WO_(3)features unidirectional and sizeable tunnels that facilitate the transport of K+ions with an even lower barrier and a high coefficient of 0.11 e V and 2.12×10^(-5)cm^(2)s^(-1),respectively.Furthermore,the introduction of alkali-metal into WO_(3)tunnels tends to introduce n-type conductivity by contributing s-electrons to the unoccupied W 5d states,resulting in enhanced conductivity and tunable electronic structures.These alkali metals in WO_(3)tunnels are prone to charge transfer,forming small polaronic states and modulating the light absorption in the visible and nearinfrared regions.These tunable electronic and optical properties,combined with the high diffusion coefficient,underscore the potential of WO_(3)in applications such as artificial synapses and chromogenic devices.