As the nano-motor becomes a mechanical reality, its prototype can be envisaged as nano-sized rotating machinery at a situation,albeit for different purposes, like that in the first half of the 20th century during whic...As the nano-motor becomes a mechanical reality, its prototype can be envisaged as nano-sized rotating machinery at a situation,albeit for different purposes, like that in the first half of the 20th century during which rotor dynamics has contributed toboosting machine power capacity. Accordingly, we take the benefit of hindsight to develop a classical framework of vibrationanalysis. Essentially, the equations of motion are formulated to cope with both the special carbon-nanotube properties and thefirst author’s previously developed spinning beam formalism, establishing a model satisfactorily verified by some availablemolecular dynamics (MD) data and classical spinning beam results extracted from the literature. The model is inexpensivebased on continuum mechanics as an alternative to the less-flexible MD method for simulating wave motion of the spinningsingle-walled carbon nanotube, yielding several interesting phenomena, including the fall-off and splitting of the wave charac-teristic curves and the unexpected gyroscopic phase property. Potential applications are proposed.展开更多
Flexible wearable sensors with excellent electric response and self-powered capability have become an appealing hotspot for personal healthcare and human-machine interfaces.Here,based on triboelectric nanogenerator(TE...Flexible wearable sensors with excellent electric response and self-powered capability have become an appealing hotspot for personal healthcare and human-machine interfaces.Here,based on triboelectric nanogenerator(TENG),a flexible self-powered tactile sensor composed of micro-frustum-arrays-structured polydimethylsiloxane(PDMS)film/copper(Cu)electrodes,and poly(vinylidenefluoride-trifluoroethylene)(P(VDF-TrFE))nanofibers has been demonstrated.The TENG-based self-powered tactile sensor can generate electrical signals through the contact-separation process of two triboelectric layers under external mechanical stimuli.Due to the uniform and controllable micro-frustum-arrays structure fabricated by micro-electro-mechanical system(MEMS)process and the P(VDF-TrFE)nanofibers fabricated by electrostatic spinning,the flexible PDMS-based sensor presents high sensitivity of 2.97 V kPa^-1,stability of 40,000 cycles(no significant decay),response time of 60 ms at 1 Hz,low detection pressure of a water drop(~4 Pa,35 mg)and good linearity of 0.99231 in low pressure region.Since the PDMS film presents ultra-flexibility and excellent-biocompatibility,the sensor can be comfortably attached on human body.Furthermore,the tactile sensor can recognize various types of human body movements by the corresponding electrical signals.Therefore,the as-prepared TENGs are potential on the prospects of gesture detection,health assessment,human-machine interfaces and so on.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.60936001, 11021262 and 11011120245)the National Basic Research Program of China (Grant No. 2007CB310500)
文摘As the nano-motor becomes a mechanical reality, its prototype can be envisaged as nano-sized rotating machinery at a situation,albeit for different purposes, like that in the first half of the 20th century during which rotor dynamics has contributed toboosting machine power capacity. Accordingly, we take the benefit of hindsight to develop a classical framework of vibrationanalysis. Essentially, the equations of motion are formulated to cope with both the special carbon-nanotube properties and thefirst author’s previously developed spinning beam formalism, establishing a model satisfactorily verified by some availablemolecular dynamics (MD) data and classical spinning beam results extracted from the literature. The model is inexpensivebased on continuum mechanics as an alternative to the less-flexible MD method for simulating wave motion of the spinningsingle-walled carbon nanotube, yielding several interesting phenomena, including the fall-off and splitting of the wave charac-teristic curves and the unexpected gyroscopic phase property. Potential applications are proposed.
基金financially supported by the National Natural Science Foundation of China(51605449,51675493 and51705476)the National Key R&D Program of China(2018YFF0300605)+2 种基金Shanxi “1331 Project” Key Subject Construction(1331KSC)the Applied Fundamental Research Program of Shanxi Province(201601D021070)Zhangjiakou Science and Technology Research and Development Plan of Zhangjiakou City(1811009B-10)
文摘Flexible wearable sensors with excellent electric response and self-powered capability have become an appealing hotspot for personal healthcare and human-machine interfaces.Here,based on triboelectric nanogenerator(TENG),a flexible self-powered tactile sensor composed of micro-frustum-arrays-structured polydimethylsiloxane(PDMS)film/copper(Cu)electrodes,and poly(vinylidenefluoride-trifluoroethylene)(P(VDF-TrFE))nanofibers has been demonstrated.The TENG-based self-powered tactile sensor can generate electrical signals through the contact-separation process of two triboelectric layers under external mechanical stimuli.Due to the uniform and controllable micro-frustum-arrays structure fabricated by micro-electro-mechanical system(MEMS)process and the P(VDF-TrFE)nanofibers fabricated by electrostatic spinning,the flexible PDMS-based sensor presents high sensitivity of 2.97 V kPa^-1,stability of 40,000 cycles(no significant decay),response time of 60 ms at 1 Hz,low detection pressure of a water drop(~4 Pa,35 mg)and good linearity of 0.99231 in low pressure region.Since the PDMS film presents ultra-flexibility and excellent-biocompatibility,the sensor can be comfortably attached on human body.Furthermore,the tactile sensor can recognize various types of human body movements by the corresponding electrical signals.Therefore,the as-prepared TENGs are potential on the prospects of gesture detection,health assessment,human-machine interfaces and so on.
