Dipankar Mandal

Institute of Nano Science and Technology | INST · Department of Physics

“Ultra-thin Films of Ferroelectric Copolymers: P(VDF-TrFE)” deal with the preparation of ultra-thin films of P(VDF-TrFE) copolymer for the application of the low cost organic non-volatile memories. Main emphases have been taken to use the photo electron and synchrotron based spectroscopy (namely XPS and NEXAFS) to insight the surface and interface...

Palladium nanoparticles (Pd-NP's) are prepared by a simple one-step procedure when poly(vinylidene fluoride) (PVDF) is used as a polymer stabilizer. High-quality Pd-NP-doped PVDF thin films are fabricated where the heat-controlled spin-coating technique is adopted. The effect of Pd-NP's on the crystal modifications and lamellae orientation in PVDF...

In this work we report on the preparation and characterization of a Poly(vinylidene fluoride) (PVDF) film doped with gold nano-particles (Au-NPs) prepared by a one step procedure. The preparation of gold Au-NPs without any external reduction agent is in the focus of interest when PVDF is used as a host polymer. It is found that a desirable amount o...

A single stage electrospinning process can give rise to preferentially oriented induced dipoles in poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] nanofibers. The piezoelectricity of as-electrospun P(VDF-TrFE) nanofiber webs opens up new possibilities for their use as a flexible nanogenerators and nano-pressure sensors. In this work, the...

Bio-piezoelectric materials are endowed with characteristic features like non-invasiveness, small energy attenuation along with deep tissue penetrability. Thus, they carry the ability to serve as both diagnostic and therapeutic modalities...

Cardiovascular diseases are found as one of the major cause of deaths globally, these can be reduced substantially if early‐stage detection and intervention is possible. Regular monitoring of the arterial pulse is one of the possible solutions, however, existing technologies have put limitations, due instability in continuous monitoring, lack of in...

Ferroelectric δ‐phase comprising polyvinylidene fluoride (δ‐PVDF) thin films are prepared via spin‐coating followed by high‐temperature annealing and rapid ice quenching, where, the requirement of a high electric field (~MV/m) is circumvented. Herein, ferroelectric responses, that is, “write,” “erase,” and “read” pulses on as prepared δ‐PVDF thin f...

Interest in the development of new generation injectable bone cements having appropriate mechanical properties, biodegradability, and bioactivity has been rekindled with the advent of nanoscience. Injectable bone cements made with calcium sulfate (CS) are of significant interest, owing to its compatibility and optimal self‐setting property. Its rap...

Mechanical and solar to electrical energy conversion using piezo- and ferroelectric and photovoltaic effects may be a practical answer to the rising energy demand. In this quest, piezoelectric polymer poly(vinylidene fluoride-hexafluoroproylene) (P(VDF-HFP)) has gained interest due to its superior piezo- and ferroelectricity. In photovoltaic applic...

In recent years, lead-free perovskite materials are exponentially emerging in photovoltaic and optoelectronic applications due to their low toxicity and superior optical properties. On the other hand, the demand for flexible, wearable, and lightweight optoelectronic devices is significantly growing in sensor and actuator technologies. In this scena...

Metal halide perovskites (MHPs) are highly emerging materials for their applications in the field of photovoltaics and optoelectronics. However, beyond these applications, the MHPs have been proven to be excellent candidates for the fabrication of self-powered nanogenerators on their own or in conjunction with piezoelectric polymers such as poly(vi...

Among the numerous types of chronic skin wounds, the treatment of diabetic foot ulcers (DFU) remains a major challenge, in view of its etiology. The high rates of amputation even with the best therapeutic regimens suggest the urgent need for newer approaches. Despite improvement in wound healing with electrical stimulation (ES), it is rarely used i...

Supramolecular assemblies with well-defined structural attenuation toward varied functional implications are an emerging area in mimicking natural biomaterials. In that regard, the redox stimuli-responsive ferrocene moiety can reversibly change between a nonpolar ferrocenyl and polar ferrocenium cation that endows interesting modular features to th...

ISBN No: 81-8372-085-4

To fabricate a high‐performance and ultrasensitive triboelectric nanogenerator (TENG), choice of a combination of different materials of triboelectric series is one of the prime challenging tasks. An effective way to fabricate a TENG with a single material (abbreviated as S‐TENG) is proposed, comprising electrospun nylon nanofibers. The surface pot...

A ferroelectret cellular structure of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] is fabricated by a 3D printing technique that exhibits a giant piezoelectric coefficient of 1200 pC/N, which is 40 times higher than its commonly known film counterpart. It attributes that the bi-polar charge separation in cellular voids upon the corona...

Currently, the demand for flexible, lightweight and portable electronic devices for high energy storage is increasing, which are important for sensors and actuators. Accordingly, flexible piezoelectric polymer nanocomposites have attracted significant attention because of their outstanding piezo-, pyro-, and ferro-electric properties. Herein, we re...

Negatively poled nylon-11 nanofibers with enhanced piezoresponse were prepared using negative bias polarity in the electrospinning setup, thereby achieving a piezoelectric charge coefficient d 33 of ∼27 pm/V; this was three times higher than their positively poled counterpart. Polarized Fourier transform infrared spectroscopy indicated that the use...

Piezo-, pyro-, ferro-electricity in carbon-fluoro polymers such as poly(vinylidene fluoride) (PVDF), its co-polymers and their nanostructures are gaining remarkable technological interest in self-powered flexible electronics. However, to achieve nanostructures of PVDF with preferred electroactive phase and enhanced piezo-electric coefficient is sti...

The novel coronavirus (COVID-19) outbreak has been announced as a “Public Health Emergency of International Concern” and further identified as a pandemic by the World Health Organization. Considering the unprecedented spread of the disease across the world, the development of noncontact and unobtrusive methods for quick screening of potential carri...

Since the early detection of COVID-19 infection in December 2019, the number of infected persons has been increasing day by day. In this present scenario, people worldwide are reorganizing their life taking safety precautions like doing frequent sanitization, wearing face masks, and avoiding social gathering to protect themselves from getting infec...

δ-phase comprising polyvinylidene fluoride (PVDF) nanoparticles are fabricated through an electrospray technique by applying a 0.1 MV/m electric field, which is 10³ times lower than the typical value, required for δ-phase transformation. X-ray diffraction and selected area electron diffraction patterns clearly indicate the δ-phase formation that li...

State-of-the-art biomedical applications including healthcare monitoring, in vivo real-time sensing and disease treatment largely relies on bio-piezoelectric platforms consisting of biocompatibility and piezoelectricity. However, the inability to design a high performance piezoelectric material with biocompatibility is the major challenges towards...

All inorganic cesium lead iodide (CsPbI3) is highly emerging in the fabrication of self-powered nanogenerators (NGs) and photodetectors (PDs) beyond the excellent performance in photovoltaic cells if it is used as one of the component in composite when engineering polymer such as PVDF is selected as an another component. In addition, the coupling o...

In this work, an all-fiber piezoelectric nanogenerator (A-PNG) is designed by using ZnO nanoparticles (NPs) reinforced poly(vinylidene fluoride) (PVDF) electrospun nanofibers as the active layer and interlocked conducting microfiber composite mats as electrodes to convert the mechanical energy into electrical power. Theoretical simulation using fin...

Delta ($\delta$) phase comprising polyvinylidene fluoride (PVDF) nanoparticles are fabricated through electrospray technique by applying 0.1 MV/m electric field at ambient temperature and pressure, which is 10$^{3}$ times lower than the typical value, required for $\delta$-phase transformation. The X-ray diffraction (XRD) and selected area electron...

Conductive hydrogels are attracting considerable interest in view of their potential in a wide range of applications that include healthcare and electronics. Such hydrogels are generally incorporated with conductive materials/polymers. Herein, we present a series of conductive hydrogels (Ch-CMC-PDA), prepared with no additional conductive material....

In this work, an all-fiber pyro- and piezo-electric nanogenerator (PPNG) is designed by multiwall carbon nanotube (MWCNT) doped poly(vinylidene fluoride) (PVDF) electrospun nanofibers as the active layer and interlocked conducting...

In this work, an all-fiber acoustoelectric nanogenerator (AAPNG) is fabricated by hydrated metal salt (MgCl2•6H2O) (Mg-salt) reinforced polyvinylidene fluoride (PVDF-Mg) nanofibers as an active layer and interlocked conducting micro-fiber based electrode for converting mechanical and acoustic energies into useful electrical power. It has been found...

The dimensional shrinkage of recent electronic components demands multifunctional sensor with less power-consuming devices. The flexible, stretchable, and skin-conformable sensor that can operate low-power personal electronics by harvesting mechanical and thermal energies from body movements and heat is of profound importance in the self-powered te...

In recent years, the piezoelectric polymers and composites have become the topic of significant research interest owing to their versatile mechanical, physical, and chemical properties. The combination of piezoelectricity with functional stuffs gives rise to interesting properties and exhibits great potential in nanoscale electromechanical devices...

The design and development of intrinsically stretchable all-organic self-powered sensors concurrently perceiving temperature and pressure remain a challenge but deliver an exciting platform to realize environmentally friendly wearable electronics. In this approach, a biomimetic all-organic stretchable energy harvester is designed by a xylitol-added...

The intervention of virus infected persons is mainly lying on diagnostic methods and COVID-19 is also not the exception. Thus, the major research direction on viral diagnosis is aligned towards biological and biomedical based approaches. In contrast, there are plenty of scope in wearable devices towards early intervention and continuous health stat...

In this work, electrospun nanofibers (NFs) (ESPUNFs) of Polyurethane (PU) have been prepared through the electrospinning process. The prepared electrospun (ESPUNFs) shows the average fiber diameter ranges from 90-225 nm while the maximum number of fibers possess diameter of 135 nm. The prepared triboelectric nanogenerator (TENG) with ESPUNFs (PU-TE...

Usage of a face mask has become mandatory in many countries after the outbreak of SARS-CoV-2, and its usefulness in combating the pandemic is a proven fact. There have been many advancements in the design of a face mask and the present treatise describes a face mask in which a simple triboelectric nanogenerator (TENG) with an electrocution layer ma...

It has been reported that the electroactive β-phase is also possible to achieve in polyvinylidene fluoride (PVDF) by selectively incorporating MOF as external filler. Furthermore electret structure in PVDF@MOF composite give rise tremendous mechano sensitivity that leads to versatile application wearable electronics, self-powered based wearable dev...

Usage of a face mask has become mandatory in many countries after the outbreak of SARS-CoV-2, and its usefulness in combating the pandemic is a proven fact. There have been many advancements in the design of a face mask and the present treatise describes a face mask in which a simple textile triboelectric nanogenerator (TENG) serves the purpose of...

Diethyl Chlorophosphate (DCP) is an important nerve agent mimic. Its misused use by terrorists and accidental release from industries creates severe panic among the general public. So, nowadays DCP sensing is of great interest to researchers. Herein, polymeric nanofibers in conjunction with 3‐(benzothiazol)‐5‐bromo‐2‐hydroxybenzaldehyde oxime (BBHO...

Flexible and wearable e-skin sensors are attracting a great interest for their smart sensing applications in next-generation electronics. However, implant ability, sensitivity and bio-signals detection capability in self-powered manner are the prime concerns in embedded devices. In particular, electrode compatibility and imperishability have become...

In this work we have streamlined our efforts towards obtaining a solution for human health monitoring system that can be used at home as well as hospital for medical issues. First, we have fabricated PVDF/MWCNT composite electrospun nanofibers followed by piezoelectric pressure sensor directly as self-powered electronic skin (e-skin). The surface m...

Perhaps the most abundant form of waste energy in our surrounding is the parasitic magnetic noise arising from electrical power transmission system. In this work, a flexible and rollable magneto-mechano-electric nanogenerator (MMENG) based wireless IoT sensor has been demonstrated in order to capture and utilize the magnetic noise. Free standing ma...

Here, we report on the preparation of a piezoelectric nanogenerator (PNG) based on reduced graphene oxide incorporated poly(vinylidene fluoride) film. A simple route of synthesis is followed to prepare rGO and the composite film (rGO-PVDF). It is found that, trace amount of rGO can induce almost 93% of electroactive phases with improved surface mor...

Here we report the design of a flexible piezoelectric-pyroelectric nanogenerator (PPNG) where both the active piezoelectric-pyroelectric component and the electrodes were composed of fiber. The active component was made with randomly oriented electrospun PVDF nano-fibers possessing electro-active β– phase. The PPNG exhibits outstanding electricity...

In this work, gold (Au) nano-particles (NPs) influenced enhanced electroactive phase nucleation in electrospun poly(vinylidene fluoride) (PVDF) nano-fibers (NFs) has been investigated. The prepared electrospun Au-PVDF composite (ESAu-PVDF) NFs possess higher content of electroactive phases (FEA∼ 92 %) than that of pure PVDF (ESNPVDF) NFs. As a resu...

In this work, poly (vinylidene fluoride)/protein composite films are prepared which is free standing and flexible. Nucleation of electroactive β-phase in poly (vinylidene fluoride) (PVDF) and consecutive surface morphological changes with different weight percentage of protein is systematically investigated. Finally, the PVDF/protein composite film...

This work introduces a piezoelectric-pyroelectric nanogenerator (P-PNG) based on methylammonium lead iodide (CH3NH3PbI3) (MAPI) incorporated electrospun poly(vinylidene fluoride) (PVDF) nanofibers that are able to harvest mechanical and thermal energies. During the application of a periodic compressive contact force at a frequency of 4 Hz, an outpu...

The recent progresses on smart technology and on Internet of Thing (IoT) have created a huge demand on development of cost-effective and environment friendly alternate energy sources, by using light weight, low cost, flexible and easily available materials. However, in this work, a new type of triboelectric driven flexible and self charging triboel...

This paper reports a self-powered, flexible, piezo- and pyro-electric hybrid nanogenerator (NG) device that can be fixed on different locations of human skin for detecting static and dynamic pressure variations and can also monitor temperature fluctuations during the respiration process. An efficient and cost-effective fabrication strategy has been...

Natural piezoelectric material is of increasing interest particularly for applications in biocompatible, implantable, and flexible electronic devices. In this paper we introduce a cost effective, easily available natural piezoelectric material, i.e., sugar in the field of wearable piezoelectric nanogenerator (PNG) where low electrical output, bioco...

Conversion of temperature fluctuations to useable electrical energy is rendered by the pyroelectric effect. Waste of heat in our day to day environment and in industrial sector constitutes an abundant source of energy. Herein, we report a pyroelectric generator (PyG) that produces pyroelectric output up to 1.5 V and 1.5 µA. Its power density is 0.0...

An integrated platform made with a piezoelectric nanogenerator (NG) is designed to convert daily human activities and acoustic vibration into useable electrical energy. The titanium dioxide (TiO2) nanoparticles (NPs) are playing a significant role as external fillers in poly(vinylidene fluoride) (PVDF) electrospun nanofiber that improves the overal...

Rapid development of wearable electronics, piezoelectric nanogenerator (PNG) has been paid a special attention due to its sustainable and accessible energy generation. In this context, we present a simple yet highly efficient design strategy to enhance the output performance of an all organic PNG (OPNG) based on multilayer assembled electrospun pol...

An all-fiber pyroelectric nanogenerator (PyNG) is fabricated where both the active pyroelectric component and the electrodes were composed of fiber. The pyroelectric component was made with randomly organized electrospun PVDF nano-fibers possessing ferroelectric β- and γ-phases. The PyNG possess higher level of sensitivity which can detect very low...

We report Eu³⁺ incorporated poly(vinylidene fluoride) (PVDF)nanocomposite film to induceelectroactive β-phase. It has been found thatsurface morphologies and crystallization properties of PVDF is markedly affected depedning on the prepration conditions and concentration of the Eu³⁺. In addition, self-poling phenomena is also observed in Eu³⁺ doped...

Here, we presented a novel, cost effective approach to fabricate flexible piezoelectric nanogenerator (NG) consisting of ZnS nanowires (NWs) grown upon cellulose. An output voltage of 4 V is generated from the nanocomposite paper (NC-paper) based NG. Subsequently, it has the capability to power Light Emitting Diode (LED) and charging up capacitor....

In this work, we demonstrate a simple and facile route ofcadmium sulfide (CdS) nanoparticle (NPs) grafted reduced graphene oxide (rGO) synthesis. It is found that a pinch (0.25 wt%) of as synthesisedCdS/rGOnanocompositecan induce more than 90% of electroactive phases in the electrospunpoly(vinylidene fluoride) (PVDF) nanofiber. Moreover, CdS/rGO na...

We report on enhanced piezoelectric properties of poly (vinylidene fluoride) (PVDF)/hectorite nano-clay composites prepared by electrospinning process. The investigation on the effects of the nano-filler in the crystalline phase and piezoelectric properties reveals dramatic enhancement of piezoelectric β-phase (95%) due to synergistic effect of ele...

Low content (0.5 wt. %) of dihydrate tin chloride (Sn²⁺) salt leads to inclusion of 98 % electroactive phase in poly(vinylidene fluoride) (PVDF), out of this a high yield of piezoelectric β-phase (∼ 49%) is found, which is most desirable for mechanical energy harvesting application. It is also found that Sn²⁺ salt can significantly enhanced the die...

Methylammonium lead bromide (CH3NH3PbBr3) (MAPbBr) has been synthesized and then introduced in the poly(vinylidene fluoride) (PVDF) nanofiber made by the process of electrospinning. The β-phase composition, degree of crystallinity as well as mechanical, optical and energy harvesting properties of this composition has been investigated. Increased el...

Methylammonium lead iodide (CH3NH3PbI3) (MAPI) embedded -phase comprising porous polyvinylidene fluoride (PVDF) composite (MPC) films turns to an excellent material for energy harvester and photodetector. MAPI enables to nucleate upto ~ 92 % of electroactive phase in PVDF to make it suitable for piezoelectric based mechanical energy harvesters (PE...

In this paper, a novel infra-red (IR) sensitive Er³⁺ modified poly(vinylidene fluoride) (PVDF) (Er-PVDF) film is developed for converting both mechanical and thermal energies into useful electrical power. The addition of Er³⁺ to PVDF is shown to improve piezoelectric properties due to the formation of a self-polarized ferroelectric β-phase and the...

A self-poled piezoelectric nanogenerator (NG) based on bismuth oxide (Bi2O3) nanostructures (BNS)-doped poly(vinylidene fluoride) (PVDF) is demonstrated. The in-situ formation of BNS incorporated in the PVDF matrix is realized through a simple solution casting technique that favors the nucleation and stabilization of 99.6% of the electroactive phas...