Heterogeneous strain engineering offers a promising approach for developing high-performance stretchable strain sensors,but the optimal strain distributions remain unexplored.Herein,we derive the optimal strain topolo...Heterogeneous strain engineering offers a promising approach for developing high-performance stretchable strain sensors,but the optimal strain distributions remain unexplored.Herein,we derive the optimal strain topology for achieving maximum sensitivities using Monte Carlo simulations,and identify the key sensitivity-regulating parameters,thus establishing a general computational design guideline.Mathematical analysis demonstrates that within the optimal topology,sensitivity is maximized by reducing the strain value of low-strain regions or increasing their area proportion.As proof of concept,patterned graphene strain sensors(PGSSs)featuring parameterized grooves are designed with their small strain values and proportions precisely modulated via finite element analysis.Adjusting these parameters enhances sensitivity by factors of~10.7 and 3.3,with the highest gauge factor reaching 25,600 at 100%strain.Furthermore,the PGSSs can effectively detect human body motions and gauge object dimensions when integrated with robot grippers.The computational framework exhibits applicability across different heterogeneous strain engineering methods.展开更多
Herein,a high strain of ~0.3% with a small hysteresis of 43% is achieved at a low electric field of 4 kV/mm in the highly <001>-textured 0.97(0.76Bi_(0.5)Na_(0.5)TiO_(3)-0.24SrTiO_(3))-0.03NaNbO_(3)(BNT-ST-0.03N...Herein,a high strain of ~0.3% with a small hysteresis of 43% is achieved at a low electric field of 4 kV/mm in the highly <001>-textured 0.97(0.76Bi_(0.5)Na_(0.5)TiO_(3)-0.24SrTiO_(3))-0.03NaNbO_(3)(BNT-ST-0.03NN)ceramics with an ergodic relaxor(ER)state,leading to a large normalized strain(d_(33)^(*))of 720 pm/V.The introduction of NN templates into BNT-ST induces the grain orientation growth and enhances the ergodicity.The highly <001>-textured BNT-ST-0.03NN ceramics display a pure ergodic relaxor state with coexisted ferroelectric R3c and antiferroelectric P4bm polar nanoregions(PNRs)on nanoscale.Moreover,due to the incomplete interdiffusion between the NN template and BNT-ST matrix,the textured ceramics present a core-shell structure with the antiferroelectric NN core,and thus the BNT-based matrix owns more R3c PNRs relative to the homogeneous nontextured samples.The high <001> crystallographic texture and more R3c PNRs both facilitate the relaxor-to-ferroelectric transition,leading to the low-field-driven high strain,while the ergodic relaxor state ensures a small hysteresis.Furthermore,the d_(33)^(*)value remains high up to 518 pm/V at 100℃ with an ultra-low hysteresis of 6%.展开更多
基金supported by the Research Center for Nature-Inspired Science and Technology,The Hong Kong Polytechnic University(Project No.:CE1T).
文摘Heterogeneous strain engineering offers a promising approach for developing high-performance stretchable strain sensors,but the optimal strain distributions remain unexplored.Herein,we derive the optimal strain topology for achieving maximum sensitivities using Monte Carlo simulations,and identify the key sensitivity-regulating parameters,thus establishing a general computational design guideline.Mathematical analysis demonstrates that within the optimal topology,sensitivity is maximized by reducing the strain value of low-strain regions or increasing their area proportion.As proof of concept,patterned graphene strain sensors(PGSSs)featuring parameterized grooves are designed with their small strain values and proportions precisely modulated via finite element analysis.Adjusting these parameters enhances sensitivity by factors of~10.7 and 3.3,with the highest gauge factor reaching 25,600 at 100%strain.Furthermore,the PGSSs can effectively detect human body motions and gauge object dimensions when integrated with robot grippers.The computational framework exhibits applicability across different heterogeneous strain engineering methods.
基金the National Key R&D Program of China(Grant No.2020YFA0711700)the National Natural Science Foundation of China(Grant No.U19A2087)+1 种基金the Special Funding Support for the Construction of Innovative Provinces in Hunan Province of China(Grant No.2020GK2062)the China National Postdoctoral Program for Innovative Talents(Grant No.BX2021377).
文摘Herein,a high strain of ~0.3% with a small hysteresis of 43% is achieved at a low electric field of 4 kV/mm in the highly <001>-textured 0.97(0.76Bi_(0.5)Na_(0.5)TiO_(3)-0.24SrTiO_(3))-0.03NaNbO_(3)(BNT-ST-0.03NN)ceramics with an ergodic relaxor(ER)state,leading to a large normalized strain(d_(33)^(*))of 720 pm/V.The introduction of NN templates into BNT-ST induces the grain orientation growth and enhances the ergodicity.The highly <001>-textured BNT-ST-0.03NN ceramics display a pure ergodic relaxor state with coexisted ferroelectric R3c and antiferroelectric P4bm polar nanoregions(PNRs)on nanoscale.Moreover,due to the incomplete interdiffusion between the NN template and BNT-ST matrix,the textured ceramics present a core-shell structure with the antiferroelectric NN core,and thus the BNT-based matrix owns more R3c PNRs relative to the homogeneous nontextured samples.The high <001> crystallographic texture and more R3c PNRs both facilitate the relaxor-to-ferroelectric transition,leading to the low-field-driven high strain,while the ergodic relaxor state ensures a small hysteresis.Furthermore,the d_(33)^(*)value remains high up to 518 pm/V at 100℃ with an ultra-low hysteresis of 6%.
