bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast stiffness variation gripper with efficient adhesion control
Authors: Chen Wenqing , Sun Tianhui , Li Jingyang , Li Xiaosong , Li Lvzhou , Meng Yonggang , Tian Yu 
Published: June 2024

Abstract
The mushroom-shape gecko-inspired adhesive has been extensively studied and applied in a wide range of fields. However, current research primarily focuses on enhancing its adhesion properties, necessitating further exploration in strategies of detachment and adaptation, which significantly constrain its practical applications. In this study, a stiffness variable gripper with controllable adhesion and fast response is developed by integrating mushroom-shape adhesive with granular jamming technology. A theoretical model for the detachment of the gripper is established, indicating the effect of backing stiffness on adhesion performance, which is verified through contact area observations and adhesion experiments. The proposed modulation method demonstrates an impressive adhesion-to-detachment ratio of 92.8, with adhesion capacity of up to 41.023 N and detachment force of only 0.442 N. The switch time is remarkably fast at just 0.5 s. Additionally, the designed gripper, under pressure difference of 60 kPa, is able to stably grasp smooth objects with various shapes weighing over 2 kg, with a load-to-weight ratio of approximately 8, and a minimal power consumption of only 4.404 W. The work here presents a comprehensive understanding of adhesion modulation of fibrillar adhesive through granular jamming, and provides new insights into robust reversible adhesion design for related technologies.
Soft robotic fingers with sensorized pre-charged finger pulp
Authors: Zhu Zihui , Yang Yang , Yan Shaoyang , Wang Songyan , Xie Yuan , Fu Yili , Li Yunquan , Jiang Pei 
Published: June 2024

Abstract
Pneumatically driven soft actuators with sensors have been developing rapidly these years. They can perceive external stimulus and be applied to different scenarios. In this study, we present a novel soft robotic finger with sensorized finger pulp based on sealing a flexible fabric piezoresistive film called Velostat into a pre-charged air bag, which can perceive the contact force with an object based on changes in resistance value of the sensor. The soft sensor mimics human finger pulp and deforms passively according to the shape of objects during grasping, so that it can firmly contact with objects and as such improves the gripper’s grasping stability. Moreover, based on force feedback, the actuator can reduce or increase the input pressure to hold the object and control the contact force precisely. The sensor exhibits a sensitivity of up to 0.328 kPa−1 and can measure pressures ranging from 0 to over 10 kPa. The sensor’s measurement range and sensitivity can be pre-adjusted by regulating the pre-charged pressure during fabrication for different grasping tasks. The response/recovery time of the sensor is 80/60 ms on average. Experiments show that the finger with sensorized pulp can be applied for object softness and size detection, object transport minitoring as well as force control grasping. The proposed soft robotic finger has potential for applications in scenarios that require safe contact and closed-loop control.
Higher-order topological Dirac phase in Y3InC: a first-principles study
Authors: Sreeparvathy P C , Villaos Rovi Angelo B , Huang Zhi-Quan , Chuang Feng-Chuan 
Published: June 2024

Abstract
Higher-order topological insulators hosting intriguing topologically protected hinge or corner states are of significant research interest. However, materials that possess higher-order topological hinge states associated with gapless bulk Dirac phases still need to be explored. Using first-principles calculations with hybrid exchange functional, we explore the electronic structure and topological properties of Y3InC and a few of its sister compounds, totaling 16 bulk materials. A symmetry-protected triple point phase, with dominated d-t
2g
character, is observed in Y3InC without spin–orbit coupling (SOC). Interestingly, the SOC induces a twin Dirac node phase in the bulk Y3InC. Furthermore, the computed Z
4 topological invariant reveals the higher-order topological nature of investigated materials. To demonstrate the gapless hinge states, we conduct edge state calculations using a rod-shaped geometry of Y3InC. Remarkably, Y3InC is identified to host multi-Dirac nodes in the bulk and surface phases together with the higher-order hinge states. These results lay the groundwork for further experimental and theoretical investigations into cubic antiperovskite materials for higher-order topological phases.
Chirality-enabled topological phase transitions in parity-time symmetric systems
Authors: Cao Yong , Sheng Lijuan , Zhou Qiang , Wang Rong , Chen Zhenkuan , Ling Xiaohui 
Published: June 2024

Abstract
Photonic spin Hall effect (PSHE) in chiral PT-symmetric systems exhibits many exotic features, but the underlying physical mechanism has not been well elucidated. Here, through rigorous calculations based on full-wave theory, we reveal the physical mechanism of the exotic PSHE and identify a chirality-enabled topological phase transition. When circularly polarized light is incident on a chiral PT-symmetric system, the transmitted beam contains two components: a spin-flipped abnormal mode that acquires a geometric phase (exhibiting a vortex or a spin-Hall shift), and a spin-maintained normal mode that does not exhibit such a phase. If the phase difference between the cross-polarized Fresnel coefficients cannot be ignored, it results in a chirality-enabled phase and intensity distribution in the abnormal mode, which induces an exotic PSHE. Consequently, as the incident angle increases, a chirality-induced topological phase transition occurs, namely the transition from the vortex generation to the exotic PSHE. Finally, we confirm that the asymmetric and periodic PSHE in the chiral slab is also related to the phase difference between the cross-polarized Fresnel coefficients. These concepts and findings also provide an opportunity for unifying the phenomena of topological phase transitions in various spin-orbit photonic systems.
Forward bias annealing of proton radiation damage in NiO/Ga2O3rectifiers
Authors: Li Jian-Sian , Chiang Chao-Ching , Wan Hsiao-Hsuan , Rasel Md Abu Jafar , Haque Aman , Kim Jihyun , Ren Fan , Chernyak Leonid , Pearton S J 
Published: June 2024

Abstract17 MeV proton irradiation at fluences from 3–7 × 1013cm−2of vertical geometry NiO/β-Ga2O3heterojunction rectifiers produced carrier removal rates in the range 120–150 cm−1in the drift region. The forward current density decreased by up to 2 orders of magnitude for the highest fluence, while the reverse leakage current increased by a factor of ∼20. Low-temperature annealing methods are of interest for mitigating radiation damage in such devices where thermal annealing is not feasible at the temperatures needed to remove defects. While thermal annealing has previously been shown to produce a limited recovery of the damage under these conditions, athermal annealing by minority carrier injection from NiO into the Ga2O3has not previously been attempted. Forward bias annealing produced an increase in forward current and a partial recovery of the proton-induced damage. Since the minority carrier diffusion length is 150–200 nm in proton irradiated Ga2O3, recombination-enhanced annealing of point defects cannot be the mechanism for this recovery, and we suggest that electron wind force annealing occurs.
High-efficiency ultra-thin GaAs solar cells based on ITO/Ag/ITO transparent electrodes and photonic crystals
Authors: Zhu Jun , Lin Sunlong , Tang Jian 
Published: June 2024

Abstract
Ultrathin photovoltaic technology has great potential to improve efficiency and reduce costs. However, achieving optical thickness requires an effective light capture strategy. In this study, for GaAs thin film solar cells with an active layer thickness of 500 nm, we adopt a combination strategy of front-end ITO/Ag/ITO transparent electrodes and back-end photonic crystals (PC). By employing the finite difference time domain (FDTD) simulation, we verify that ITO/Ag/ITO transparent electrodes and AlGaAs PC can effectively enhance the light-harvesting capacity of cells. The proposed cell structure has a spectral absorption rate (SAR) of 0.9781 in the visible wavelength range. To further optimize the photovoltaic performance parameters, we optimize the doping concentration of the pn junction in the cell. Finally, the short circuit current density

J

s
c

,

open circuit voltage

V

o
c

,

fill factor (FF) and photoelectric conversion efficiency (PCE) of GaAs thin film solar cells are successfully increased to

31.10

mA

cm

−
2

,

1.28

V
,

88.18% and 35.12%, respectively. This provides crucial experimental validation and theoretical guidance for advancing ultra-thin photovoltaic technology.
Interfacial charge and temperature analysis of gate-all-around line tunneling TFET for improved device reliability
Authors: Karthik Kadava R N , Pandey Chandan Kumar 
Published: June 2024

Abstract
In this article, the impact of interface-trap charges (ITCs) on the DC and analog/RF parameters of gate-all-around vertical TFET (GAA-VTFET) are considered to evaluate the reliability of the device. ITCs are included at oxide/semiconductor interface of GAA-VTFET where the probability of occurrence of traps are high owing to faults in the manufacturing process. A detailed investigation is carried out by tuning the temperature, polarities and density of ITCs. It is clearly observed from TCAD based simulation results that the presence of traps alters the flat-band voltage, thereby affecting the overall performance of the device. Transfer characteristics of the device depicts that impact of traps shows more variation in the OFF-state current than the ON-current. However, presence of donor traps improves the analog/RF parameter, such as parasitic capacitances (Cgg), Transconductance (gm), cut-off frequency (fT), output resistance (Rout) etc. Furthermore, the simulation results proclaim that GAA-VTFET shows more resilient to acceptor traps than the positive traps. Moreover, by examining the influence of ambient temperature on device performance, it is revealed that the drain current in the subthreshold region (at low gate bias) is more susceptible to the degradation than the super-threshold region at elevated temperature. This is mainly due to the superiority of the trap-assisted tunneling (TAT) and Shockley-Read-Hall (SRH) recombination mechanisms over the band-to-band tunneling (BTBT). When the raise in ambient temperature is tuned between minimum of 200 K to maximum of 400 K, it is observed that OFF-current increases by ∼7 times. Lastly, voltage-transfer characteristics (VTC) analysis of the resistive-load inverter clearly demonstrates that the influence of traps on the noise margin is within acceptable limits.
Development of a low-frequency broadband sound absorber based on a micro-perforated panel coupled with the Helmholtz resonator system
Authors: Li Qi , Wu Jinwu , Mao Qibo , Jv Xin , Chen Minghao 
Published: June 2024

Abstract
In the field of vibration and noise reduction, micro-perforated panel (MPP) structures and Helmholtz resonators (HR) play crucial roles as common sound-absorbing elements. However, independently applied MPP and HR structures cannot provide sufficiently wide absorption bandwidths at low frequencies. To achieve low-frequency broadband sound absorption, this study proposes a novel low-frequency broadband sound absorption structure (EMH) based on MPP and HR with a thickness of 40 mm to achieve a subwavelength, efficient, and compact design. We establish theoretical models of MPP and HR coupled systems, systematically analyze the sound absorption performance of same-element and different-element coupled structures, and employ the particle swarm optimization (PSO) algorithm to obtain structural parameters for efficient coupled sound absorption. Furthermore, we compare the sound absorption performance of three optimized coupled structures (MPP-coupled (SM), HR-coupled (SH), and MPP and HR-coupled) from the perspective of the theoretical calculation of the sound absorption coefficient and finite element analysis of the sound absorption mechanism. Finally, samples fabricated using 3D printing technology are tested in an impedance tube. The results demonstrate that efficient coupled sound absorption of MPP and HR can be achieved through parameter optimization. SH and SM exhibit nearly perfect sound absorption in the frequency ranges of 323–495 Hz and 615–1600 Hz, respectively, whereas the effective absorption bandwidth of EMH can reach 1225 Hz in the range of 200–1600 Hz. EMH shows superior low-frequency broadband sound absorption performance with a lightweight and simple structure, which holds the potential for application in low-frequency noise control.
Design and fabrication of a multi-purpose four arm electrothermal microgripper; a novel approach to control maximum gripping force limit
Authors: Barati Hamed , Barazandeh Farshad , Jabari Alireza , Akbari Mohammad , Golshani Vahid , Asgari Mohammad 
Published: June 2024

Abstract
The development of microgrippers requires accurate control of force and position for the grasping mechanisms in micromanipulation. This controllability ensures the safe transfer of sensitive micro-objects, such as living cells. The design of microgrippers is often limited by the dimensions and adaptability of the micro-objects being manipulated. Therefore, microgrippers should be customized for each micro-object. Additionally, complex sensor mechanisms are required to control the gripping force. This study introduces a novel design of a four-arm MEMS electrothermal microgripper intended for versatile micromanipulation purposes. The microgripper design procedure is compatible with a list of constraints, including biological and microfabrication constraints. The jaw form is designed to manipulate micro-objects with a wide range of dimensions (1 to 360 μm). Furthermore, a novel approach is presented here to control the force threshold of gripping without a sensor during manipulation. The proposed solution involves using structure stiffening to control the force and prevent damage to micro-objects. GA and analytical models (transient behaviour of structure) are used to satisfy the long list of constraints. The device is fabricated through UV-LIGA, utilizing nickel and copper as the structural and sacrificial layer. The experimental and simulation results demonstrate that the microgripper can achieve a 60 μm jaw displacement at a voltage of 0.329V. The gripping arms can provide a force of 15 to 450 μN for the handling of micro-objects. The maximum gripper temperature of 98 °C makes it suitable for biological applications. The innovative form and systematic design of the microgripper enable its adaptability for various applications.
Large valley splitting induced by spin-orbit coupling effects in monolayer Hf3N2O2
Authors: Qiao Shiqian , Zhang Yang , Lan Mengxian , Ji Zhiqiang , Song Shuhua , Qu Weichun , Wu Hong , Pu Yong , Li Feng 
Published: June 2024

Abstract
Valleytronics is an emerging field of electronics that aims to utilize valley degrees of freedom in materials for information processing and storage. Nowadays, the valley splitting of 2D materials is not particularly large, therefore, the search for large valley splitting materials is very important for the development of valleytronics. This work theoretically predicts that MXene Hf3N2O2 is a 2D material with large valley splitting. It is an indirect bandgap semiconductor with a bandgap of 0.32 eV at the PBE level and increases to 0.55 eV at the HSE06 level. Since Hf3N2O2 breaks the symmetry of spatial inversion, when we consider spin–orbit coupling (SOC), there is a valley splitting at K/K′ of the valence band with a valley splitting value of 98.76 meV. The valley splitting value slightly decreases to 88.96 meV at the HSE06 level. In addition, The phonon spectrum and elastic constants indicate that it is both dynamically and mechanically stable. According to the maximum localization of the Wannier function, it is obtained that the Berry curvature is not zero at K/K′. When a biaxial strain is applied, Hf3N2O2 transitions from metal to semiconductor. With increasing biaxial strain, the valley splitting value increased from 70.13 meV to 109.11 meV. Our research shows that Hf3N2O2 is a promising material for valleytronics.
Metasurface loaded dual port circularly polarized dielectric resonator antenna with reduced RADAR cross section and mutual coupling features
Authors: Tripathi Meenakshi , Sharma Anand , Kumar Vinay 
Published: June 2024

Abstract
The design of dual port radiator with a polarization diversity technique and reduced radar cross section (RCS) is described in this study. Cross slot is used to stimulate cylindrical ceramic for generating circular polarization features. Mirror orientation of aperture between port-1 and port-2 improves the isolation level by 25 dB. To suppress the antenna’s monostatic RCS, split ring resonator (SRR) based frequency selective surface is positioned between and around the dual ports. Experimental outcomes confirm the designed radiator operates from 4.11–5.24 GHz along with 3-dB axial ratio in between 4.15–4.92 GHz. The value of monostatic RCS is reduced by 15 dBsm in between the operating band. Broadsided radiation characteristics and good value of diversity parameter makes the designed radiator applicable for C-band Radar applications.
Deconfinement of runaway electrons by local vertical magnetic field perturbation
Authors: Dutta Someswar , Sharma Deepti , Tanna R.L. , Ghosh J. , Raju D. 
Published: June 2024

Abstract
Runaway electron (RE) deconfinement and subsequent suppression is of prime importance for successful long-term operation of any tokamak. In this work, to deconfine and mitigate REs, the efficacy of local vertical field (LVF) perturbation has been explored numerically. LVF perturbation-assisted RE loss studies are carried out by simulating the drift orbits of the REs in magnetostatic perturbed fields and estimating the resulting orbit losses for different initial energies and magnitudes of LVF perturbation. To this end, the pre-existing PARTICLE code has been extended to the relativistic full-orbit-following code PARTICLE-3D (P3D) integrated with the magnetic field calculation code EFFI and plasma equilibrium field calculation code IPREQ to include the required fields for studying particle dynamics in general; this is then used to numerically model LVF perturbation-assisted RE deconfinement experiments conducted in the ADITYA tokamak. Simulation results show a significant (∼90%) deconfinement of REs with the application of LVF perturbation of a suitable amplitude (∼0.1% of the total magnetic field) in a preferred direction. The existence of a threshold magnitude of the applied field is also established, which is observed to be dependent on the energy of the REs. The simulation results reproduce all the experimental observations and reveal other interesting features of RE mitigation using LVF perturbation. The temporal map of orbiting time of REs shows that REs originating from the inboard side edge region (

ψ

N > 0.5) of the plasma are relatively more prone to be lost with the application of suitable LVF perturbation than those originating from the plasma core. Interestingly, the simulation results demonstrate the existence of strong correlation between the safety factor (q) profile in the plasma edge region (

ψ

N > 0.7) and the level of RE deconfinement using LVF perturbation.
Higher integrability for measures satisfying a PDE constraint
Authors: Arroyo-Rabasa Adolfo , De Philippis Guido , Hirsch Jonas , Rindler Filip , Skorobogatova Anna 
Published: June 2024

We establish higher integrability estimates for constant-coefficient systems of linear PDEs
\[

A

μ
=
σ
,

\mathcal {A} \mu = \sigma ,

\]
where

μ
∈

M

(
Ω
;
V
)

\mu \in \mathcal {M}(\Omega ;V)

and

σ
∈

M

(
Ω
;
W
)

\sigma \in \mathcal {M}(\Omega ;W)

are vector measures and the polar

d

μ

d

|

μ

|

\frac {\mathrm {d}\mu }{\mathrm {d}|\mu |}

is uniformly close to a convex cone of

V
V

intersecting the wave cone of

A

\mathcal {A}

only at the origin. More precisely, we prove local compensated compactness estimates of the form
\[

‖
μ

‖

L

p

(

Ω
′

)

≲

|

μ

|

(
Ω
)
+

|

σ

|

(
Ω
)
,

Ω
′

⋐
Ω
.

\|\mu \|_{\mathrm {L}^p(\Omega ’)} \lesssim |\mu |(\Omega ) + |\sigma |(\Omega ), \qquad \Omega ’ \Subset \Omega .

\]
Here, the exponent

p
p

belongs to the (optimal) range

1
≤
p
>
d

/

(
d
−
k
)

1 \leq p > d/(d-k)

,

d
d

is the dimension of

Ω
\Omega

, and

k
k

is the order of

A

\mathcal {A}

. We also obtain the limiting case

p
=
d

/

(
d
−
k
)

p = d/(d-k)

for canceling constant-rank operators. We consider applications to compensated compactness and applications to the theory of functions of bounded variation and bounded deformation.
A Mañé-Manning formula for expanding measures for endomorphisms of ℙ^{𝕜}
Authors: Bianchi Fabrizio , He Yan Mary 
Published: June 2024

Let

k
≥
1

k \ge 1

be an integer and

f
f

a holomorphic endomorphism of

P

k

(

C

)

\mathbb {P}^k (\mathbb {C})

of algebraic degree

d
≥
2

d\geq 2

. We introduce a dynamical volume dimension for ergodic

f
f

-invariant probability measures with strictly positive Lyapunov exponents. In particular, this class of measures includes all ergodic measures whose measure-theoretic entropy is strictly larger than

(
k
−
1
)
log
⁡
d

(k-1)\log d

, a natural generalization of the class of measures of positive measure-theoretic entropy in dimension 1. The volume dimension is equivalent to the Hausdorff dimension when

k
=
1

k=1

, but depends on the dynamics of

f
f

to incorporate the absence of an analogue of Koebe’s theorem and the non-conformality of holomorphic endomorphisms for

k
≥
2

k\geq 2

.

If

ν
\nu

is an ergodic

f
f

-invariant probability measure with strictly positive Lyapunov exponents, we prove a generalization of the Mañé-Manning formula relating the volume dimension, the measure-theoretic entropy, and the sum of the Lyapunov exponents of

ν
\nu

. As a consequence, we give a characterization of the first zero of a natural pressure function for such expanding measures in terms of their volume dimensions. For hyperbolic maps, such zero also coincides with the volume dimension of the Julia set, and with the exponent of a natural (volume-)conformal measure. This generalizes results by Denker-Urbański [Nonlinearity 4 (1991), pp. 365–384; Trans. Amer. Math. Soc. 328 (1991), pp. 563–587] and McMullen [Comment. Math. Helv. 75 (2000), pp. 535–593] in dimension 1 to any dimension

k
≥
1

k\geq 1

.

Our methods mainly rely on a theorem by Berteloot-Dupont-Molino [Ann. Inst. Fourier (Grenoble) 58 (2008), pp. 2137–2168], which gives a precise control on the distortion of inverse branches of endomorphisms along generic inverse orbits with respect to measures with strictly positive Lyapunov exponents.