Molecule‐Assembled Plasmonic Gold Nanoparticle Network for Piezophototronic and Human Activity Detections

Abstract

Strain-based complex functionalities in response to external physical stimuli are significant for the development of intelligent robotic systems. Herein, an assembly of gold nanoparticles through ligand interaction with short linker molecule 2-picolylamine (PA) is developed. With subnanometer spacing between the nanoparticles (NPs), the network exhibits strain sensitive carrier tunneling between them. Based on these NP networks and a lithographically patterned polydimethylsiloxane (PDMS) microstructure, a multistimuli-responsive tactile sensor is developed that effectively transduces mechanical strain to electrical responses, and can identify variable weights, detect finger touch patterns, and is ultrasensitive to vibrational movements. Physical activities such as jogging, leg movements, and sit-to-stand postures are identified using the system. A significantly high gauge factor of 243 AE 10 associated with the Au NP-PA network is recorded. In addition, the sensor exhibits strain-dependent plasmonic photodetection with a responsivity of 309 mA W À1 at a tensile strain of 3.7%. The multistimuli-responsive Au NP-PA network demonstrated here opens up new perspectives on the development of intelligent multifunctional systems.

Cobalt-substituted ZnS QDs: a diluted magnetic semiconductor and efficient photocatalyst

“…These two isotherms were found to match with the typical type IV adsorption isotherm, which conrmed the presence of a mesoporous structure. 21,44 Due to the strong quantum connement effect of pure and doped ZnS QDs, there was no signicant change in the isotherms and the obtained values of specic surface areas for Co-00 (ZnS) and Co-09 (ZnS) samples are 89.87 m 2 g −1 and 93.07 m 2 g −1 along with the associated pore radii 3.27 nm and 3.28 nm respectively. All the obtained results from the BET study were also aligned with the X-ray diffraction data.…”

Nanocrystalline Ni–Zn spinel ferrites: size-dependent physical, photocatalytic and antioxidant properties

“…The higher specic surface area of ZNF-1 nanoparticles enables more contact sites for photocatalytic reactions and as a result the photodegradation of dye becomes faster compared to other samples. 3,14 Study of photocatalytic effects Fig. 6(a)-(c) show the photodegradation of MB using Ni-Zn ferrite nanocatalysts (ZNF-1, ZNF-2 and ZNF-3) under the illumination of a xenon lamp.…”

“…Because of the magnetic behaviour of ferrite nanoparticles, it is easier to separate them using a strong magnet. 14,15 In the entire cubic spinel ferrite family, nanocrystalline Ni-Zn spinel ferrites are known for their so ferrimagnetic and semiconducting nature, having a moderate Néel temperature. These magnetic nanomaterials also exhibit excellent chemical and thermal stability, opening the door to various technological applications.…”