Transcranial Acoustic Metamaterial Parameters Inverse Designed by Neural Networks

Objective:The objective of this work is to investigate the mapping relationship between transcranial ultrasound image quality and transcranial acoustic metamaterial parameters using inverse design methods.Impact Statement:Our study provides insights into inverse design methods and opens the route to guide the preparation of transcranial acoustic metamaterials.Introduction:The development of acoustic metamaterials has enabled the exploration of cranial ultrasound,and it has been found that the influence of the skull distortion layer on acoustic waves can be effectively eliminated by adjusting the parameters of the acoustic metamaterial.However,the interaction mechanism between transcranial ultrasound images and transcranial acoustic metamaterial parameters is unknown.Methods:In this study,1,456 transcranial ultrasound image datasets were used to explore the mapping relationship between the quality of transcranial ultrasound images and the parameters of transcranial acoustic metamaterials.Results:The multioutput parameter prediction model of transcranial metamaterials based on deep back-propagation neural network was built,and metamaterial parameters under transcranial image evaluation indices are predicted using the prediction model.Conclusion:This inverse big data design approach paves the way for guiding the preparation of transcranial metamaterials.

Mechanochemical transformation of fluorescent hydrogel based on dynamic lanthanide-terpyridine coordination

As a burgeoning research field, ultrasound-responsive materials have attracted intense interest in healthcare research. However, the basic mechanism of sonochemical effect in the quasi-solid state is far from being well understood than those in the solution. Herein, we showcase mechanochemical transformations of europium(Ⅲ) complexes in a supramolecular hydrogel matrix. With the combination of labile terpyridine-europium complexes(TPY-Eu^(3+)) as mechanochromic moieties and an ultrasound-responsive fluorogen(URF) as a molecular tweezer, the hydrogel produces a notable fluorescence change in response to ultrasound. The mechanochemical transformation was elucidated by molecular dynamics(MD) simulations, and fully probed and evidenced by electrochemical experiments, X-ray photoelectron spectroscopy(XPS), and attenuated total reflectance-Fourier transform infrared(ATR-FTIR) spectroscopy.

The Dynamic Mortise-and-Tenon Interlock Assists Hydrated Soft Robots Toward Off-Road Locomotion

Natural locomotion such as walking,crawling,and swimming relies on spatially controlled deformation of soft tissues,which could allow efficient interaction with the external environment.As one of the ideal candidates for biomimetic materials,hydrogels can exhibit versatile bionic morphings.However,it remains an enormous challenge to transfer these insitu deformations to locomotion,particularly above complex terrains.Herein,inspired by the crawling mode of inchworms,an isotropic hydrogel with thermoresponsiveness could evolve to an anisotropic hydrogel actuator via interfacial diffusion polymerization,further evolving to multisection structure and exhibiting adaptive deformation with diverse degrees of freedom.Therefore,a dynamic mortise-and-tenon interlock could be generated through the interaction between the self-deformation of the hydrogel actuator and rough terrains,inducing continual multidimensional locomotion on various artificial rough substrates and natural sandy terrain.Interestingly,benefiting from the powerful mechanical energy transfer capability,the crawlable hydrogel actuators could also be utilized as hydrogel motors to activate static cargos to overstep complex terrains,which exhibit the potential application of a biomimetic mechanical discoloration device.Therefore,we believe that this design principle and control strategy may be of potential interest to the field of deformable materials,soft robots,and biomimetic devices.