Deep-Learning-Assisted Underwater 3D Tactile Tensegrity

The growth of underwater robotic applications in ocean exploration and research has created an urgent need for effective tactile sensing.Here,we propose an underwater 3-dimensional tactile tensegrity(U3DTT)based on soft self-powered triboelectric nanogenerators and deep-learning-assisted data analytics.This device can measure and distinguish the magnitude,location,and orientation of perturbations in real time from both flow field and interaction with obstacles and provide collision protection for underwater vehicles operation.It is enabled by the structure that mimics terrestrial animals’musculoskeletal systems composed of both stiff bones and stretchable muscles.Moreover,when successfully integrated with underwater vehicles,the U3DTT shows advantages of multiple degrees of freedom in its shape modes,an ultrahigh sensitivity,and fast response times with a low cost and conformability.The real-time 3-dimensional pose of the U3DTT has been predicted with an average root-mean-square error of 0.76 in a water pool,indicating that this developed U3DTT is a promising technology in vehicles with tactile feedback.

Development of surface displaying system for heterologous protein expression in Candida tropicalis

The purpose of this study was to assess the potential application of cell surface display in Candida tropicalis.Surface display gene cassettes were constructed using five anchoring proteins from Saccharomyces cerevisiae,three of which[(suppression of exponential defect protein,SED1),(cell wall protein 2,CWP2)and(delayed anaerobic protein 4,DAN4)]were reported to show higher activity of heterologous proteins thanα-agglutinin(AGα1).The performance of yeast-enhanced green fluorescent protein(yeGFP)was evaluated using laser scanning confocal microscopy and flow cytometry.The results showed that the three anchoring regions(SED1,CWP2 and AGα1)successfully displayed yeGFP on the cell wall.To investigate the effect of the three anchoring proteins on the surface display of Rhizopus oryzaeα-amylase(ROA1)and Aspergillus aculeatusβ-glucosidase(BGL1)in C.tropicalis,we constructed surface display gene cassettes for ROA1 and BGL1,respectively.The strains containing the anchoring proteins SED1 and CWP2 showed higher activity of ROA1 and BGL1 than the strains containing the anchoring protein AGα1.The highest ROA1 and BGL1 activities of strains with SED1 were 6.37 U/g CDW and 7.93 U/g CDW,respectively,which were sixfold and eightfold higher than those of strain with AGα1.In addition,we also optimized signal peptides.The results indicated that signal peptides have an impact on enzyme activity.

Optimized pre-treatment of high strength food waste digestate by high content aluminum-nanocluster based magnetic coagulation

Coagulation-based pre-treatment efficiency of high strength digestate of food waste(HSDFW) anaerobic digestion is negated by organic ligand-catalyzed decomposition of coagulants. In this study, an efficient HSDFW pre-treatment method, magnetic seeds(MS) coagulation, was employed by using highly stable Keggin Al_(30) nanocluster(PAC_(30)), MS and polyacrylamide(PAM), and its operation was optimized by evaluating the performance of removing turbidity, total suspended solids(TSS), chemical oxygen demand(COD), and total phosphorous(TP) phosphate. Results showed that at the optimum dosage of 4.82 g/L, PAC_(30) demonstrated excellent removals as high as 98.93% ± 0.1% of turbidity, 98.04% ± 0.1% of TSS, 58.28% ± 0.3% of total COD, 99.98% ± 0.01% of TP and 99.50% ± 0.01% of dissolved phosphate, respectively. Apparent molecular weight(AMW) and three-dimensional excitation-emission matrix(3 D-EEM) fluorescence spectroscopy analyses demonstrated more efficient removal of dissolved organic matter(DOM), particularly non-biodegradable and hydrophobic components by PAC_(30) than commercial coagulant. The sedimentation was much improved from 40 min by coagulation/flocculation to about 5 min settling by MS coagulation. The PAC_(30) based magnetic coagulation(MC) presents theoretical guidance on a cost-effective and much less footprint pre-treatment alternative for high strength wastewater.

A bio-inspired and self-powered triboelectric tactile sensor for underwater vehicle perception

Marine mammals relying on tactile perception for hunting are able to achieve a remarkably high prey capture rate without visual or acoustic perception.Here,a self-powered triboelectric palm-like tactile sensor(TPTS)is designed to build a tactile perceptual system for underwater vehicles.It is enabled by a three-dimensional structure that mimics the leathery,granular texture in the palms of sea otters,whose inner neural architecture provides additional clues indicating the importance of tactile information.With the assistance of palm structure and triboelectric nanogenerator technology,the proposed TPTS has the ability to detect and distinguish normal and shear external load in real-time and approximate the external stimulation area,especially not affected by the touch frequency,that is,it can maintain stable performance under high-frequency contact.The results show that the TPTS is a promising tool for integration into grippers mounted on underwater vehicles to complete numerous underwater tasks.

A Triboelectric-Based Artificial Whisker for Reactive Obstacle Avoidance and Local Mapping

Since designing efficient tactile sensors for autonomous robots is still a challenge,this paper proposes a perceptual system based on a bioinspired triboelectric whisker sensor(TWS)that is aimed at reactive obstacle avoidance and local mapping in unknown environments.The proposed TWS is based on a triboelectric nanogenerator(TENG)and mimics the structure of rat whisker follicles.It operates to generate an output voltage via triboelectrification and electrostatic induction between the PTFE pellet and copper films(0.3 mm thickness),where a forced whisker shaft displaces a PTFE pellet(10 mm diameter).With the help of a biologically inspired structural design,the artificial whisker sensor can sense the contact position and approximate the external stimulation area,particularly in a dark environment.To highlight this sensor’s applicability and scalability,we demonstrate different functions,such as controlling LED lights,reactive obstacle avoidance,and local mapping of autonomous surface vehicles.The results show that the proposed TWS can be used as a tactile sensor for reactive obstacle avoidance and local mapping in robotics.