9 research outputs found
Ultra-light-weight microwave X-band EMI shielding or RAM material made from sustainable pyrolysed cork templates
Cork is a renewable and sustainable material, highly porous and lightweight. We valorised waste cork and recycled wine stoppers to make pyrolysed/carbonised solid cork, for use as economic and sustainable microwave (MW) absorbers at the microwave X-band (8-12 GHz), without binder or additives. Although cork is already a very lightweight material (0.16 g/cm3), the pyrolysed cork is five-times less dense at 0.031 g/cm3, was amorphous graphitic carbon, and had an excellent shielding effectiveness (SET) of -18 to -38 dB, depending on thickness, with attenuation of the electromagnetic energy through internal reflection within the cellular cork structure. Furthermore, this ultra-light-weight material has an extremely high MW specific shielding effectiveness or efficiency (SSE), between -640 to -1235 dB g-1 cm3 over the entire X-band range, depending on thickness (3.0-8.6 mm), one of the highest reported for any pure carbon material. this upper value being more than twice that of any previously reported graphite-based foams
Screen-Printable Electronic Ink of Ultrathin Boron Nitride Nanosheets
Two-dimensional
materials play a vital role in the current electronic
industry in the fabrication of devices. In the present work, we have
exfoliated and stabilized the insulating hexagonal boron nitride (hBN)
by means of a polymer-assisted liquid-phase technique. Further, the
highly viscous ink of hBN was prepared, and its printability on various
commercially available substrates was studied. The morphology of the
printed patterns reveals the layered arrangement of hBN. The various
electrical and dielectric characterizations, carried out on a metalāinsulatorāmetal
capacitor, testified its potential applications in various fields
of printed electronics
Can zinc aluminate-titania composite be an alternative for alumina as microelectronic substrate?
Abstract
Alumina, thanks to its superior thermal and dielectric properties, has been the leading substrate over several decades, for power and microelectronics circuits. However, alumina lacks thermal stability since its temperature coefficient of resonant frequency (Ļf) is far from zero (ā60āppmKā»Ā¹). The present paper explores the potentiality of a ceramic composite 0.83ZnAlāOā-0.17TiOā (in moles, abbreviated as ZAT) substrates for electronic applications over other commercially-used alumina-based substrates and synthesized using a non-aqueous tape casting method. The present substrate has Ļf ofā+ā3.9āppmKā»Ā¹ and is a valuable addition to the group of thermo-stable substrates. The ZAT substrate shows a high thermal conductivity of 31.3āWmā»Ā¹Kā»Ā¹ (thermal conductivity of alumina is about 24.5āWmā»Ā¹Kā»Ā¹), along with promising mechanical, electrical and microwave dielectric properties comparable to that of alumina-based commercial substrates. Furthermore, the newly-developed substrate material shows exceptionally good thermal stability of dielectric constant, which cannot be met with any of the alumina-based HTCC substrates
High-Performance Flexible Piezoelectric Nanogenerator Based on Electrospun PVDF-BaTiO<sub>3</sub> Nanofibers for Self-Powered Vibration Sensing Applications
In the present era of intelligent electronics and Internet
of Things
(IoT), the demand for flexible and wearable devices is very high.
Here, we have developed a high-output flexible piezoelectric nanogenerator
(PENG) based on electrospun poly(vinylidene fluoride) (PVDF)-barium
titanate (BaTiO3) (ES PVDF-BT) composite nanofibers with
an enhanced electroactive phase. On addition of 10 wt % BaTiO3 nanoparticles, the electroactive Ī²-phase of the PVDF
is found to be escalated to ā¼91% as a result of the synergistic
interfacial interaction between the tetragonal BaTiO3 nanoparticles
and the ferroelectric host polymer matrix on electrospinning. The
fabricated PENG device delivered an open-circuit voltage of ā¼50
V and short-circuit current density of ā¼0.312 mA mā2. Also, the PVDF-BT nanofiber-based PENG device showed an output
power density of ā¼4.07 mW mā2, which is 10
times higher than that of a pristine PVDF nanofiber-based PENG device.
Furthermore, the developed PENG has been newly demonstrated for self-powered
real-time vibration sensing applications such as for mapping of mechanical
vibrations from faulty CPU fans, hard disk drives, and electric sewing
machines
High-Performance Flexible Piezoelectric Nanogenerator Based on Electrospun PVDF-BaTiO<sub>3</sub> Nanofibers for Self-Powered Vibration Sensing Applications
In the present era of intelligent electronics and Internet
of Things
(IoT), the demand for flexible and wearable devices is very high.
Here, we have developed a high-output flexible piezoelectric nanogenerator
(PENG) based on electrospun poly(vinylidene fluoride) (PVDF)-barium
titanate (BaTiO3) (ES PVDF-BT) composite nanofibers with
an enhanced electroactive phase. On addition of 10 wt % BaTiO3 nanoparticles, the electroactive Ī²-phase of the PVDF
is found to be escalated to ā¼91% as a result of the synergistic
interfacial interaction between the tetragonal BaTiO3 nanoparticles
and the ferroelectric host polymer matrix on electrospinning. The
fabricated PENG device delivered an open-circuit voltage of ā¼50
V and short-circuit current density of ā¼0.312 mA mā2. Also, the PVDF-BT nanofiber-based PENG device showed an output
power density of ā¼4.07 mW mā2, which is 10
times higher than that of a pristine PVDF nanofiber-based PENG device.
Furthermore, the developed PENG has been newly demonstrated for self-powered
real-time vibration sensing applications such as for mapping of mechanical
vibrations from faulty CPU fans, hard disk drives, and electric sewing
machines
High-Performance Flexible Piezoelectric Nanogenerator Based on Electrospun PVDF-BaTiO<sub>3</sub> Nanofibers for Self-Powered Vibration Sensing Applications
In the present era of intelligent electronics and Internet
of Things
(IoT), the demand for flexible and wearable devices is very high.
Here, we have developed a high-output flexible piezoelectric nanogenerator
(PENG) based on electrospun poly(vinylidene fluoride) (PVDF)-barium
titanate (BaTiO3) (ES PVDF-BT) composite nanofibers with
an enhanced electroactive phase. On addition of 10 wt % BaTiO3 nanoparticles, the electroactive Ī²-phase of the PVDF
is found to be escalated to ā¼91% as a result of the synergistic
interfacial interaction between the tetragonal BaTiO3 nanoparticles
and the ferroelectric host polymer matrix on electrospinning. The
fabricated PENG device delivered an open-circuit voltage of ā¼50
V and short-circuit current density of ā¼0.312 mA mā2. Also, the PVDF-BT nanofiber-based PENG device showed an output
power density of ā¼4.07 mW mā2, which is 10
times higher than that of a pristine PVDF nanofiber-based PENG device.
Furthermore, the developed PENG has been newly demonstrated for self-powered
real-time vibration sensing applications such as for mapping of mechanical
vibrations from faulty CPU fans, hard disk drives, and electric sewing
machines