Highly sensitive strain sensors based on piezotronic tunneling junction

Abstract

Piezotronics with capacity of constructing adaptive and seamless interactions between electronics/machines and human/ambient are of value in Internet of Things, artificial intelligence and biomedical engineering. Here, we report a kind of highly sensitive strain sensor based on piezotronic tunneling junction (Ag/HfO2/n-ZnO), which utilizes the strain-induced piezoelectric potential to control the tunneling barrier height and width in parallel, and hence to synergistically modulate the electrical transport process. The piezotronic tunneling strain sensor has a high on/off ratio of 478.4 and high gauge factor of 4.8 × 105 at the strain of 0.10%, which is more than 17.8 times larger than that of a conventional Schottky-barrier based strain sensor in control group as well as some existing ZnO nanowire or nanobelt based sensors. This work provides in-depth understanding for the basic mechanism of piezotronic modulation on tunneling junction, and realizes the highly sensitive strain sensor of piezotronic tunneling junction on device scale, which has great potential in advanced micro/nano-electromechanical devices and systems.

Unveiling the Surface Structure of ZnO Nanorods and H2 Activation Mechanisms with 17O NMR Spectroscopy

“…ZnO (zinc oxide), a semiconducting material with a direct band gap of 3.4 eV and a large binding energy of 60 meV, exhibits many promising properties including piezoelectricity, pyroelectricity, and biocompatibility. 1 It attracts a lot of research attention and finds a variety of applications including luminescent materials, 2 sensors, 3 supercapacitors, 4 batteries, 5,6 solar cells, 7,8 and catalysts. 9,10 For catalytic applications, in particular, ZnO is a critical component of Cu/ZnO/Al 2 O 3 industrial catalysts for methanol synthesis from H 2 /CO/CO 2 11 and plays a very important part in the direct synthesis of light olefins from syngas 12,13 and propane dehydrogenation, 14 yet the detailed mechanisms are still under debate.…”

“…ZnO (zinc oxide), a semiconducting material with a direct band gap of 3.4 eV and a large binding energy of 60 meV, exhibits many promising properties including piezoelectricity, pyroelectricity, and biocompatibility . It attracts a lot of research attention and finds a variety of applications including luminescent materials, sensors, supercapacitors, batteries, , solar cells, , and catalysts. , For catalytic applications, in particular, ZnO is a critical component of Cu/ZnO/Al 2 O 3 industrial catalysts for methanol synthesis from H 2 /CO/CO 2 and plays a very important part in the direct synthesis of light olefins from syngas , and propane dehydrogenation, yet the detailed mechanisms are still under debate. ,− In these processes, the interaction between H 2 and ZnO is believed to be crucial , and has been investigated extensively. IR studies suggested two types of chemisorption of H 2 on ZnO in general, including type I featuring the formation of Zn–H and O–H, − and type II with bridging hydride Zn–H–Zn and O–H···O species, − and these hydride species were found particularly active for catalytic hydrogenation reactions .…”

Melamine sponge skeleton loaded organic conductors for mechanical sensors with high sensitivity and high resolution

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Liquid metal-embedded hydrogel sensors for unsupervised learning enabled sign-to-verbal translation

“…Wearable sensors that transducing a physical stimulus into electrical signals can track human status and surrounding information by translating these physical stimuli into electrical signals 1,2,3,4 , which have played a vital role in the development of the Internet of Things 5,6,7 , soft robotics 8,9,10 , bioelectronics 11,12,13 , and artificial intelligence 14 . However, these conventional sensors face substantial challenges, such as difficulty in achieving conformable contact or 3D coupling with bio-tissues' curvilinearity.…”