The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micr...The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micro-devices. Based on this approach, formation of complex 3D configurations with suspended curvy features or hierarchical geometries remains a challenge. In this paper, we incorporate the prestrained shape memory polymer in the 2D precur- sor design to enable local rolling deformations after the mechanical assembly through compressive buckling. A theoretical model captures quantitatively the effect of key design parameters on local rolling deformations. The combination of precisely controlled global buckling and local rolling expands substantially the range of accessible 3D configurations. The combined experimental and theoretical studies over a dozen of examples demonstrate the utility of the proposed strategy in achieving complex reprogrammable 3D mesostructures.展开更多
Recent progress in the synthesis and deterministic assembly of advanced classes of single crystalline inorganic semiconductor nanomaterial establishes a foundation for high-performance electronics on bendable,and even...Recent progress in the synthesis and deterministic assembly of advanced classes of single crystalline inorganic semiconductor nanomaterial establishes a foundation for high-performance electronics on bendable,and even elastomeric,substrates.The results allow for classes of systems with capabilities that cannot be reproduced using conventional wafer-based technologies.Specifically,electronic devices that rely on the unusual shapes/forms/constructs of such semiconductors can offer mechanical properties,such as flexibility and stretchability,traditionally believed to be accessible only via comparatively low-performance organic materials,with superior operational features due to their excellent charge transport characteristics.Specifically,these approaches allow integration of high-performance electronic functionality onto various curvilinear shapes,with linear elastic mechanical responses to large strain deformations,of particular relevance in bio-integrated devices and bio-inspired designs.This review summarizes some recent progress in flexible electronics based on inorganic semiconductor nanomaterials,the key associated design strategies and examples of device components and modules with utility in biomedicine.展开更多
Variations in parameters associated with the ambient environment can introduce noise in soft,body-worn sensors.For example,many piezoresistive pressure sensors exhibit a high degree of sensitivity to fluctuations in t...Variations in parameters associated with the ambient environment can introduce noise in soft,body-worn sensors.For example,many piezoresistive pressure sensors exhibit a high degree of sensitivity to fluctuations in temperature,thereby requiring active compensation strategies.The research presented here addresses this challenge with a multilayered 3D microsystem design that integrates four piezoresistive sensors in a full-Wheatstone bridge configuration.An optimized layout of the sensors relative to the neutral mechanical plane leads to both an insensitivity to temperature and an increased sensitivity to pressure,relative to previously reported devices that rely on similar operating principles.Integrating this 3D pressure sensor into a soft,flexible electronics platform yields a system capable of real-time,wireless measurements from the surface of the skin.Placement above the radial and carotid arteries yields high-quality waveforms associated with pulsatile blood flow,with quantitative correlations to blood pressure.The results establish the materials and engineering aspects of a technology with broad potential in remote health monitoring.展开更多
Temporal and spatial expression of cosignaling receptors and their ligands regulates the early stages of T-cell activation(signal 1,T-cell receptor(TCR)signaling and signal 2,costimulation/coinhibition),clonal expansi...Temporal and spatial expression of cosignaling receptors and their ligands regulates the early stages of T-cell activation(signal 1,T-cell receptor(TCR)signaling and signal 2,costimulation/coinhibition),clonal expansion and T-cell survival during their differentiation towards effector T cells.Once the inflammatory stimulus is eliminated,effector T cells return to homeostasis after undergoing a contraction phase by activation-induced cell death and the intervention of ligands for coinhibitory receptors,leaving a population of long-term memory T cells.The expression of ligands for coinhibitory receptors on hematopoietic cells and,more importantly,on non-hematopoietic cells of peripheral tissues is a key process in tuning the functional activity of effector T cells to prevent excess tissue inflammation that may lead to immunopathology and subsequent tissue dysfunction.展开更多
Recent research establishes methods of controlled mechanical assembly as versatile routes to three-dimensional(3D)mesostructures from patterned 2D films,with demonstrated applicability to a broad range of materials(e....Recent research establishes methods of controlled mechanical assembly as versatile routes to three-dimensional(3D)mesostructures from patterned 2D films,with demonstrated applicability to a broad range of materials(e.g.,semiconductors,polymers,metals,and their combinations)and length scales(e.g.,from sub-microscale to centimeter scale).Previously reported schemes use pre-stretched elastomeric substrates as assembly platforms to induce compressive buckling of 2D precursor structures,thereby enabling their controlled transformation into 3D architectures.Here,we introduce tensile buckling as a different,complementary strategy that bypasses the need for a pre-stretched platform,thereby simplifying the assembly process and opening routes to additional classes of 3D geometries unobtainable with compressive buckling.A few basic principles in mechanics serve as guidelines for the design of 2D precursor structures that achieve large out-of-plane motions and associated 3D transformations due to tensile buckling.Experimental and computational studies of nearly 20 examples demonstrate the utility of this approach in the assembly of complex 3D mesostructures with characteristic dimensions from micron to millimeter scales.The results also establish the use of nonlinear mechanics modeling as a mechanism for designing systems that yield desired 3D geometries.A strain sensor that offers visible readout and large detectable strain range through a collection of mechanically triggered electrical switches and LEDs serves as an application example.展开更多
Implantable deep brain stimulation(DBS)systems are utilized for clinical treatment of diseases such as Parkinson's disease and chronic pain.However,long-term efficacy of DBS is limited,and chronic neuroplastic cha...Implantable deep brain stimulation(DBS)systems are utilized for clinical treatment of diseases such as Parkinson's disease and chronic pain.However,long-term efficacy of DBS is limited,and chronic neuroplastic changes and associated therapeutic mechanisms are not well understood.Fundamental and mechanistic investigation,typically accomplished in small animal models,is difficult because of the need for chronic stimulators that currently require either frequent handling of test subjects to charge battery-powered systems or specialized setups to manage tethers that restrict experimental paradigms and compromise insight.To overcome these challenges,we demonstrate a fully implantable,wireless,battery-free platform that allows for chronic DBS in rodents with the capability to control stimulation parameters digitally in real time.The devices are able to provide stimulation over a wide range of frequencies with biphasic pulses and constant voltage control via low-impedance,surface-engineered platinum electrodes.The devices utilize off-the-shelf components and feature the ability to customize electrodes to enable broad utility and rapid dissemination.Efficacy of the system is demonstrated with a readout of stimulation-evoked neural activity in vivo and chronic stimulation of the medial forebrain bundle in freely moving rats to evoke characteristic head motion for over 36 days.展开更多
Precise,quantitative in vivo monitoring of hydration levels in the near surface regions of the skin can be useful in preventing skinbased pathologies,and regulating external appearance.Here we introduce multimodal sen...Precise,quantitative in vivo monitoring of hydration levels in the near surface regions of the skin can be useful in preventing skinbased pathologies,and regulating external appearance.Here we introduce multimodal sensors with important capabilities in this context,rendered in soft,ultrathin,‘skin-like’formats with numerous advantages over alternative technologies,including the ability to establish intimate,conformal contact without applied pressure,and to provide spatiotemporally resolved data on both electrical and thermal transport properties from sensitive regions of the skin.Systematic in vitro studies and computational models establish the underlying measurement principles and associated approaches for determination of temperature,thermal conductivity,thermal diffusivity,volumetric heat capacity,and electrical impedance using simple analysis algorithms.Clinical studies on 20 patients subjected to a variety of external stimuli validate the device operation and allow quantitative comparisons of measurement capabilities to those of existing state-of-the-art tools.展开更多
基金X.G. and Z.X. contributed equally to this work. Y.Z. acknowledges the support from the National Natural Science Foundation of China （Grant Nos. 11502129 and 11722217） and the Tsinghua National Laboratory for Information Science and Technology. Y.H. acknowledges the support from the NSF （Grant Nos. CMMI1400169, CMMI1534120 and CMMI1635443）. X.G. acknowledges the support from the National Natural Science Foundation of China （Grant Nos. 11702155）.
文摘The mechanically guided assembly that relies on the compressive buckling of strate- gically patterned 2D thin films represents a robust route to complex 3D mesostructures in advanced materials and even functional micro-devices. Based on this approach, formation of complex 3D configurations with suspended curvy features or hierarchical geometries remains a challenge. In this paper, we incorporate the prestrained shape memory polymer in the 2D precur- sor design to enable local rolling deformations after the mechanical assembly through compressive buckling. A theoretical model captures quantitatively the effect of key design parameters on local rolling deformations. The combination of precisely controlled global buckling and local rolling expands substantially the range of accessible 3D configurations. The combined experimental and theoretical studies over a dozen of examples demonstrate the utility of the proposed strategy in achieving complex reprogrammable 3D mesostructures.
基金the Yonsei University Future-leading Research Initiative of 2017(RMS22017-22-00).
文摘Recent progress in the synthesis and deterministic assembly of advanced classes of single crystalline inorganic semiconductor nanomaterial establishes a foundation for high-performance electronics on bendable,and even elastomeric,substrates.The results allow for classes of systems with capabilities that cannot be reproduced using conventional wafer-based technologies.Specifically,electronic devices that rely on the unusual shapes/forms/constructs of such semiconductors can offer mechanical properties,such as flexibility and stretchability,traditionally believed to be accessible only via comparatively low-performance organic materials,with superior operational features due to their excellent charge transport characteristics.Specifically,these approaches allow integration of high-performance electronic functionality onto various curvilinear shapes,with linear elastic mechanical responses to large strain deformations,of particular relevance in bio-integrated devices and bio-inspired designs.This review summarizes some recent progress in flexible electronics based on inorganic semiconductor nanomaterials,the key associated design strategies and examples of device components and modules with utility in biomedicine.
基金supported by a grant from Kyung Hee University in 2022(KHU-20220916)。
文摘Variations in parameters associated with the ambient environment can introduce noise in soft,body-worn sensors.For example,many piezoresistive pressure sensors exhibit a high degree of sensitivity to fluctuations in temperature,thereby requiring active compensation strategies.The research presented here addresses this challenge with a multilayered 3D microsystem design that integrates four piezoresistive sensors in a full-Wheatstone bridge configuration.An optimized layout of the sensors relative to the neutral mechanical plane leads to both an insensitivity to temperature and an increased sensitivity to pressure,relative to previously reported devices that rely on similar operating principles.Integrating this 3D pressure sensor into a soft,flexible electronics platform yields a system capable of real-time,wireless measurements from the surface of the skin.Placement above the radial and carotid arteries yields high-quality waveforms associated with pulsatile blood flow,with quantitative correlations to blood pressure.The results establish the materials and engineering aspects of a technology with broad potential in remote health monitoring.
基金grant FIS PI#13/00029(Fondo de Investigaciones Sanitarias,Ministry of Health,Spanish Government and cofunded by the European Union ERDF/ESF,“Investing in your future”)LE093U13 and Unit of Excellence Research UIC#012(Department of Education of the Regional Government,Junta de Castilla y Leon)+3 种基金Gerencia Regional de Salud(BIO/01/15)which were awarded to J.I.R.B.Miguel Servet National Grant(Health National Organization Research)CP12/03063,CPII17/00002 and FIS PI16/00002(Instituto de Salud Carlos III and cofunded by European Union ERDF/ESF,“Investing in your future”)Gerencia Regional de Salud GRS963/A/2014,GRS1142/A/2015 and GRS1505/A/2017 funded the research of M.L.R.G.The National Network CIBERONC(Oncology Research Program,referenced as CB16/12/00480)also cofunded this work.P.S.is funded by grant 31003A-176356 of the Swiss National Science Foundation.A.W.is funded by the grants Deutsche Krebshilfe(70112451)Deutsche Forschungsgemeinschaft(SFB1039,and FOR2438).
文摘Temporal and spatial expression of cosignaling receptors and their ligands regulates the early stages of T-cell activation(signal 1,T-cell receptor(TCR)signaling and signal 2,costimulation/coinhibition),clonal expansion and T-cell survival during their differentiation towards effector T cells.Once the inflammatory stimulus is eliminated,effector T cells return to homeostasis after undergoing a contraction phase by activation-induced cell death and the intervention of ligands for coinhibitory receptors,leaving a population of long-term memory T cells.The expression of ligands for coinhibitory receptors on hematopoietic cells and,more importantly,on non-hematopoietic cells of peripheral tissues is a key process in tuning the functional activity of effector T cells to prevent excess tissue inflammation that may lead to immunopathology and subsequent tissue dysfunction.
基金Y.Z.acknowledges support from the National Natural Science Foundation of China(#11672152 and#11722217)the Thousand Young Talents Program of China,and the Tsinghua National Laboratory for Information Science and TechnologyY.H.acknowledges the support from the NSF(#CMMI1400169,#CMMI1534120,and#CMMI1635443).
文摘Recent research establishes methods of controlled mechanical assembly as versatile routes to three-dimensional(3D)mesostructures from patterned 2D films,with demonstrated applicability to a broad range of materials(e.g.,semiconductors,polymers,metals,and their combinations)and length scales(e.g.,from sub-microscale to centimeter scale).Previously reported schemes use pre-stretched elastomeric substrates as assembly platforms to induce compressive buckling of 2D precursor structures,thereby enabling their controlled transformation into 3D architectures.Here,we introduce tensile buckling as a different,complementary strategy that bypasses the need for a pre-stretched platform,thereby simplifying the assembly process and opening routes to additional classes of 3D geometries unobtainable with compressive buckling.A few basic principles in mechanics serve as guidelines for the design of 2D precursor structures that achieve large out-of-plane motions and associated 3D transformations due to tensile buckling.Experimental and computational studies of nearly 20 examples demonstrate the utility of this approach in the assembly of complex 3D mesostructures with characteristic dimensions from micron to millimeter scales.The results also establish the use of nonlinear mechanics modeling as a mechanism for designing systems that yield desired 3D geometries.A strain sensor that offers visible readout and large detectable strain range through a collection of mechanically triggered electrical switches and LEDs serves as an application example.
基金support from the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health T32EB000809(A.B.)the ARCS Foundation(A.B.).The University of Arizona Department of Biomedical Engineering startup funds(P.G.)and Core Facilities Pilot Program(CA-CFPP NANO-3310342)(P.G.).5.M.W.acknowledges the support by the MSIT(Ministry of Science and IC〇,Korea,under the ICT Creative Consilience program(IITP-2020-0-01821)+2 种基金by Nano Material Technology Development Program(2020M3H4A1A03084600)through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT of KoreaThe Eunice Kennedy Shriver National Institute of Child Health&Human Development(K12HD073945,F.V.).University of Pennsylvania Department of Neurosurgery startup funds(A.G.R.).
文摘Implantable deep brain stimulation(DBS)systems are utilized for clinical treatment of diseases such as Parkinson's disease and chronic pain.However,long-term efficacy of DBS is limited,and chronic neuroplastic changes and associated therapeutic mechanisms are not well understood.Fundamental and mechanistic investigation,typically accomplished in small animal models,is difficult because of the need for chronic stimulators that currently require either frequent handling of test subjects to charge battery-powered systems or specialized setups to manage tethers that restrict experimental paradigms and compromise insight.To overcome these challenges,we demonstrate a fully implantable,wireless,battery-free platform that allows for chronic DBS in rodents with the capability to control stimulation parameters digitally in real time.The devices are able to provide stimulation over a wide range of frequencies with biphasic pulses and constant voltage control via low-impedance,surface-engineered platinum electrodes.The devices utilize off-the-shelf components and feature the ability to customize electrodes to enable broad utility and rapid dissemination.Efficacy of the system is demonstrated with a readout of stimulation-evoked neural activity in vivo and chronic stimulation of the medial forebrain bundle in freely moving rats to evoke characteristic head motion for over 36 days.
基金YM and XF acknowledge the support from the National Basic Research Program of China(Grant No.2015CB351900)National Natural Science Foundation of China(Grant Nos.11402135,11320101001)+2 种基金YH acknowledges the support from NSF(Grant Nos.DMR1121262,CMMI1300846,CMMI1400169,and CMMI1534120)the NIH(Grant No.R01EB019337)RCW acknowledges support from the National Science Foundation under grant no.DGE-1144245.
文摘Precise,quantitative in vivo monitoring of hydration levels in the near surface regions of the skin can be useful in preventing skinbased pathologies,and regulating external appearance.Here we introduce multimodal sensors with important capabilities in this context,rendered in soft,ultrathin,‘skin-like’formats with numerous advantages over alternative technologies,including the ability to establish intimate,conformal contact without applied pressure,and to provide spatiotemporally resolved data on both electrical and thermal transport properties from sensitive regions of the skin.Systematic in vitro studies and computational models establish the underlying measurement principles and associated approaches for determination of temperature,thermal conductivity,thermal diffusivity,volumetric heat capacity,and electrical impedance using simple analysis algorithms.Clinical studies on 20 patients subjected to a variety of external stimuli validate the device operation and allow quantitative comparisons of measurement capabilities to those of existing state-of-the-art tools.
