Preoperative planning of three axis intersection surgical laparoscopic arm system based on characteristic parameters.

Purpose: The application of robotics in the field of minimally invasive surgery solves some shortcomings of traditional minimally invasive surgery. Preoperative planning is an important prerequisite for the successful completion of robot-assisted surgery. The optimization of surgical incision position and the initial location of surgical robot are two important parts of preoperative planning.

Smart Sensing Multifunctionalities Based on Barium Strontium Titanate Thin Films.

Sensors that have low power consumption, high scalability and the ability of rapidly detecting multitudinous external stimulus are of great value in cyber-physical interactive applications. Herein, we reported the fabrication of ferroelectric barium strontium titanate ((BaSr)TiO, BST) thin films on silicon substrates by magnetron sputtering. The as-grown BST films have a pure perovskite structure and exhibit excellent ferroelectric characteristics, such as a remnant polarization of 2.

Momentarily trapped exciton polaron in two-dimensional lead halide perovskites.

Two-dimensional (2D) lead halide perovskites with distinct excitonic feature have shown exciting potential for optoelectronic applications. Compared to their three-dimensional counterparts with large polaron character, how the interplay between long- and short- range exciton-phonon interaction due to polar and soft lattice define the excitons in 2D perovskites is yet to be revealed. Here, we seek to understand the nature of excitons in 2D CsPbBr perovskites by static and time-resolved spectroscopy which is further rationalized with Urbach-Martienssen rule.

Efficient hot-electron extraction in two-dimensional semiconductor heterostructures by ultrafast resonant transfer.

Energy loss from hot-carrier cooling sets the thermodynamic limit for the photon-to-power conversion efficiency in optoelectronic applications. Efficient hot-electron extraction before cooling could reduce the energy loss and leads to efficient next generation devices, which, unfortunately, is challenging to achieve in conventional semiconductors. In this work, we explore hot-electron transfer in two-dimensional (2D) layered semiconductor heterostructures, which have shown great potential for exploring new physics and optoelectronic applications.

Controlling Exciton and Valley Dynamics in Two-Dimensional Heterostructures with Atomically Precise Interlayer Proximity.

Two-dimensional (2D) materials and heterostructures with strong excitonic effect and spin/valley properties have emerged as an exciting platform for optoelectronic and spin/valleytronic applications. There, precise control of the exciton transformation process (including intralayer to interlayer exciton transition and recombination) and valley polarization process structural tuning is crucial but remains largely unexplored. Here, using hexagonal boron nitride (BN) as an intermediate layer, we show the fine-tuning of exciton and valley dynamics in 2D heterostructures with atomic precision.

Highly efficient hot electron harvesting from graphene before electron-hole thermalization.

Although the unique hot carrier characteristics in graphene suggest a new paradigm for hot carrier-based energy harvesting, the reported efficiencies with conventional photothermoelectric and photothermionic emission pathways are quite low because of inevitable hot carrier thermalization and cooling loss. Here, we proposed and demonstrated the possibility of efficiently extracting hot electrons from graphene after carrier intraband scattering but before electron-hole interband thermalization, a new regime that has never been reached before. Using various layered semiconductors as model electron-accepting components, we generally observe ultrafast injection of energetic hot electrons from graphene over a very broad photon energy range (visible to mid-infrared).

Dielectric Environment-Robust Ultrafast Charge Transfer Between Two Atomic Layers.

Understanding electron transfer across two-dimensional (2D) van der Waals (vdW) interfaces especially the effect of dielectric environment not only contributes to the rational design of high performance optoelectronic and photo/electrocatalytic devices but also unravels the nature of charge motion. Herein, we investigated the electron transfer process between two atomic thin layered materials coupled by vdW force at ultimate proximity. Despite their susceptible electronic properties, we show electron transfer at 2D vdW interface is robust and ultrafast (∼30 fs), regardless of the surrounding dielectrics and solvents.