Design and validation a minimally invasive robotic surgical instrument with decoupled pose and multi-DOF.

High-performance miniature surgical instruments play an important role in complicated minimally invasive surgery (MIS). Based on in-depth analysis of the requirements of MIS and the characteristics of the existing minimally invasive surgical instruments, a multiple degrees of freedom (DOF) robotic surgical instrument with decoupled pose was proposed. Firstly, the design concept of the pose decoupling instrument was described in detail, and its physical structure, transmission structure, and mechanical properties were designed and analyzed. A surgical instrument control algorithm based on the master-slave mode was established. Finally, a physical prototype was developed, and its motion ranges of joints, load capacity, and suture operation performance were comprehensively evaluated, which confirmed the effectiveness of the proposed minimally invasive robotic surgical instrument.

Design of a dexterous robotic surgical instrument with a novel bending mechanism.

BACKGROUND: The robot-assisted minimally invasive surgery (RMIS) has developed rapidly in recent years, requiring highly articulated instruments to enable surgeons to perform complicated and precise procedures. METHODS: A novel wrist-type surgical instrument was proposed for RMIS. The wrist consists of superelastic-wire-driven snake-like joints and universal joints, which could perform two deflections and one distal rotation. The bending mechanism and the kinematics of universal joints were analysed. The forward and inverse kinematics of the wrist were derived. RESULTS: The performances of the instrument were evaluated using a prototype by experiments. The average motion deviation of the wrist's deflection was 0.15 ± 0.08 mm, and the maximum deviation was 0.52 mm. The maximum payload capability was 10 N. The suture task and ex vivo procedure verified the effectiveness of the instrument. CONCLUSIONS: The proposed instrument has high dexterity and payload capability, which contributes to improving the quality of the RMIS procedures.

Design and implementation of a hand-held robot-assisted minimally invasive surgical device with enhanced intuitive manipulability and stable grip force.

BACKGROUND: The conventional hand-held minimally invasive surgical devices commonly suffer from non-intuitive manipulability and restricted flexibility for operation. METHODS: A hand-held surgical device with enhanced intuitive manipulability and stable grip force was proposed for minimally invasive surgery (MIS). The dexterous instrument and isomorphic handle were designed, and the cable transmission structure and model of the instrument were analysed. A modelling method for grip force pre-compensation was proposed to produce stable grip forces under different posture. RESULTS: The prototype of the proposed MIS device was developed, and the related experiments were carried out. The maximum opening angle error was 1.2°. Compared with the non-compensation model, the variation of grip force reduced 8 times with the pre-compensation model. The animal vivo experiments verified the feasibility and practicability of the device. CONCLUSIONS: The proposed hand-held device could provide intuitive manipulability and stable operation, which contributes to the performance improvement of the MIS.

Efficiency improvement of silicon nanostructure-based solar cells.

Solar cells based on a high-efficiency silicon nanostructure (SNS) were developed using a two-step metal-assisted electroless etching (MAEE) technique, phosphorus silicate glass (PSG) doping and screen printing. This process was used to produce solar cells with a silver nitrate (AgNO3) etching solution in different concentrations. Compared to cells produced using the single MAEE technique, SNS-based solar cells produced with the two-step MAEE technique showed an increase in silicon surface coverage of ~181.1% and a decrease in reflectivity of ~144.3%. The performance of the SNS-based solar cells was found to be optimized (~11.86%) in an SNS with a length of ~300 nm, an aspect ratio of ~5, surface coverage of ~84.9% and a reflectivity of ~6.1%. The ~16.8% increase in power conversion efficiency (PCE) for the SNS-based solar cell indicates good potential for mass production.

Rice-straw-like structure of silicon nanowire arrays for a hydrogen gas sensor.

A rice-straw-like silicon nanowire (SiNW) array was developed for hydrogen gas sensing applications. The straight-aligned SiNW array sensor was first fabricated by the metal-assisted electroless etching (MAEE) technique. Rice-straw-like SiNW arrays were formed using a repeated MAEE technique. Hydrogen sensing characteristics were measured for gas concentrations from 20 to 1000 ppm at room temperature. The rice-straw-like SiNW-array-based hydrogen gas sensor performed with low noise and a high response (232.5%) for 1000 ppm hydrogen gas. It was found that the rice-straw-like SiNW-array hydrogen gas sensor had a much better response (approximately 2.5 times) than the straight-aligned SiNW-array sensor. The rice-straw-like SiNW-array structure effectively increased the surface area and the concentration of silicon oxide, which provided additional binding sites for gas molecules. Thus, the rice-straw-like SiNW-array-based hydrogen gas sensor possessed good sensing properties and has the potential for mass production of sensing devices.

Gas ionization sensors with carbon nanotube/nickel field emitters.

Gas ionization sensors based on the field emission properties of the carbon nanotube/nickel (CNT/Ni) field emitters were first developed in this work. It is found that the breakdown electric field (E(b)) slightly decreases from 2.2 V/microm to 1.9 V/microm as the pressure of H2 gas increases from 0.5 Torr to 100 Torr. On the contrary, E(b) obviously increases from 2.9 V/microm to 6.5 V/microm as O2 gas pressure increases from 0.5 Torr to 100 Torr. This may be explained by the depression of the electron emission that caused by the adsorption of the O2 gas on the CNT emitters. The Raman spectra of the CNT/Ni emitters also show that more defects were generated on the CNTs after O2 gas sensing. The Joule heating effect under high current density as performing H2 sensing was also observed. These effects may contribute the pressure dependence on the breakdown electric field of the CNT/Ni gas ionization sensors.