Kumkum Ahmed

Shibaura Institute of Technology · College of Engineering

Porous polymers have been successfully obtained by an addition reaction of hexamethylene diisocyanate (HDI) trimer, isocyanurate type (IHDI), biuret type (BHDI), adduct type (AHDI), and dithiol compounds in toluene using triethyl amine (TEA) as a base catalyst. The feed ratio of TEA and the molecular structure of monomers affect the surface morphol...

Soft tactile sensors have been extensively studied due to their promising potential in estimating applied forces while exhibiting mechanical compliance. Such sensors have been fabricated from a variety of composite materials and various techniques to advance their applications. Currently, the development of soft tactile sensor based on carbon nanot...

New biobased polycaprolactone (PCL) nanocomposite materials were prepared using cellulose-zinc oxide (NCC-ZnO) as an organic–inorganic nanofiller which was prepared by loading zinc oxide (ZnO) onto the surface of nanocrystalline cellulose (NCC). Various loadings (2–8 wt%) of nanofiller were added onto the PCL matrix to prepare PCL/NCC-ZnO nanocompo...

Four-dimensional (4D) printing of soft functional materials such as polymeric hydrogels, elastomers, and macromolecular systems has grown significant interest in the field of robotics and bionics due to their sophisticated morphing behavior such as deformation, shrinkage, swelling, and morphology. Furthermore, the mechanical and biocompatibility ch...

Ionic liquids (ILs) are molten salts that are entirely composed of ions and have melting temperatures below 100 C. When immobilized in polymeric matrices by sol–gel or chemical polymerization, they generate gels known as ion gels, ionogels, ionic gels, and so on, which may be used for a variety of electrochemical applications. One of the most signi...

Michael-addition reactions between multifunctional-acetoacetate, meso-erythritol tetra-acetoacetate (ETAA), d-sorbitol hexa-acetoacetate (SHAA), and poly(ethylene glycol) diacrylate (PEGDA) have been investigated to obtain network polymers. The reactions in mixtures of ethanol (EtOH) and dimethyl sulfoxide (DMSO) using 1,8-diazabicyclo[5.4.0]undeca...

Michael-addition reactions of multi-functional acetoacetate, meso-erythritol tetraacetoacetate (ETAA), trimethylolpropane triacetoacetate (TPTAA), and diacrylate compounds, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, or poly(ethylene glycol) diacrylate (PEGDA), in dimethyl sulfoxide have successfully yielded the...

In this work, we present the structural analysis of 3D/4D printable N,N-dimethylacryla-mide (DMAAm)-co-stearyl acrylate (SA) and/or lauryl acrylate (LA)-based shape memory gels (SMGs). We characterized these gels by scanning microscopic light scattering technique (SMILS) where a time-and space-averaged correlation function is obtained to overcome t...

3D food printing sectors require comprehensive knowledge on viscoelastic and mechanical properties of diverse food materials in order to effectively utilize them in rapid and customized 3D production for supply and manufacturing chains. In this work, we present mechanical and rheological properties of Agar and Konjac based edible gels at different...

Multi-walled carbon nanotubes (MWCNTs) without and with adsorbed silver nanoparticles (Ag-NPs), are used to detect acetone vapour. MWCNTs are grown on SiO2/Si substrates and silver (Ag) nanoparticles (NPs) are deposited onto some of these MWCNTs using electron beam evaporation method. The sensitivity of CNT based sensors (with and without NPs) incr...

In this work, we report the synthesis of ion-conductive gels, or ionic gels, via thiol-ene click reactions. The novel gel systems consist of the multifunctional thiol monomers tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate (TEMPIC), pentaerythritol tetrakis(3-mercaptopropionate) (PEMP), and dipentaerythritol hexakis(3-mercaptopionate) (DPMP) as...

Porous polymers with macr/micro- sized pores have potential applications in separation, batteries, fuel cells and sensors [1, 2]. Thiol-ene "click" is a widespread method for monolith preparation owing to its exceptional versatility, simplicity and facile tunability. In our previous work, we reported on the fabrication of extremely soft type thiol-...

Wide band gap semiconductors such as ZnO are characterized by unique optoelectronic properties, which have led to numerous applications in the field of sensors and optoelectronics. These components are commonly fabricated on rigid substrates. However, the same synthesis method cannot be used to fabricate these components on flexible substrates. In...

In this work, 3D printable gel polymer electrolytes (GPEs) based on N,N-dimethylacrylamide (DMAAm) and polyvinylidene fluoride (PVDF) in lithium chloride containing ethylene glycol solution are synthesized and their physicochemical properties are investigated. 3D printing is carried out with a customized stereolithography type 3D gel printer named...

4D printing is based on 3D printing technology with an added dimension, where the printed structure evolves as a function of time. Materials that are stimuli-responsive are used for 4D printing such as shape memory alloys and polymers etc. Once these materials are 3D printed, they can morph into complex geometries on being exposed to external stimu...

３Ｄ印刷するのに好適な性質を備えるとともに、３Ｄ印刷した物品が良好な機械的性質と導電性とを兼ね備える、導電性複合材料を提供する。 【解決手段】カーボンナノチューブ、イオン液体、ポリイオン液体、及びポリマーを含む、導電性複合材料であって、カーボンナノチューブが、導電性複合材料全体の質量を基準として５質量％を超える量で含まれ、イオン液体が、導電性複合材料全体の質量を基準として３０質量％〜５０質量％の量で含まれ、ポリイオン液体が、導電性複合材料全体の質量を基準として１０質量％〜３５質量％の量で含まれ、ポリマーが、ポリマーの質量：前記ポリイオン液体の質量の比が４：６〜６：４の量で含まれることを特徴とする、導電性複合材料。

Smart or stimuli-responsive materials are getting increasing attentions due to their advantageous applications in numerous sectors, such as sensors and actuators, tissue engineering, bio-separation devices, and controlled drug delivery. Fabrication of smart materials via 3D printing process is still in its infancy and this hindering widespread impl...

Porous polymers have been synthesized by Michael addition reactions of multi-functional acrylate and diamine or dithiol compounds. Aza-Michael addition reaction of multi-functional acrylate, trimethylolpropane propoxylate triacrylate (TPT) and hexamethylene diamine (HDA) in dimethyl sulfoxide (DMSO) successfully yielded the porous polymer. The poro...

In this work, we have developed 3D printable shape memory hydrogels (SMGs) using a customized 3D printer. These 3D printable smart material has been used in 4D printing concept to create biomimetic untethered hydrogel actuator with soft robotic functions. Conductive property also has been added to printable SMGs for human motion sensing. Additional...

The polymer gel is composed of polymeric chains which are crosslinked in a three-dimensional (3D) network structure and liquid which is widely applied to tissue engineering, medical treatment, and solid state electrochemical devices. The gel contains a large amount of water inside the three-dimensional network structure. The human body is also most...

Hydrogel actuators with soft‐robotic functions and biomimetic advanced materials with facile and programmable fabrication processes remain scarce. A novel approach to fabricating a shape‐memory‐hydrogel‐(SMG)‐based bilayer system using 3D printing to yield a soft actuator responsive to the methodical application of swelling and heat is introduced....

Highly conductive, soft, and 3D-printable nanocomposite polymers have been developed that consists of poly (ionic liquid) (PIL), polymethylmethacrylate (PMMA) as polymeric system, multiwalled carbon nanotubes (MWCNTs) as fillers and an ionic liquid (IL) that acts as a plasticizer and dopant for the MWCNTs. The nanocomposites exhibited variable mech...

Showcasing research from the group of Prof. Hidemitsu Furukawa, Soft and Wet matter Engineering laboratory (SWEL) of the Department of Mechanical Systems Engineering, Yamagata University, Japan. 3D printing of shape memory hydrogels with tunable mechanical properties 3D printing of highly robust thermoresponsive poly(dimethyl acrylamide-co-stearyl...

Front Cover: In article 1800216 by Hidemitsu Furukawa and co‐workers, ionic gels utilizing a thiol‐ene reaction in ionic liquid (IL) are developed and 3D printed for the first time. The gels are very soft, transparent and conductive. The properties of the gels are highly dependent on the constituent end‐crosslinkers functionalities, acrylate monome...

A series of 3D printable multifunctional ionic gels (IGs) are developed incorporating ionic liquid (IL) in the thiol–ene network of thiol‐based end‐crosslinker and acrylate monomers. The resulted gels, termed as thiol‐ionic gels (T‐IGs), are highly transparent and very soft with IL content of 70–85 wt%. The mechanical and conductive properties of t...

In microfabricated MEMS actuator, sensor and biomedical devices, soft polymeric materials like PDMS are widely used for lightweight, low cost, high corrosion resistance, high flexibility and high dimensional stability. Along with their numerous beneficial functions these materials have some shortcomings during real application for their hydrophobic...

Hydrogels are capable of absorbing large amounts of liquid or biological fluids in three-dimensional polymeric networks. The properties of smart gels can be controlled or tuned by external stimuli such as heat, optics, solvent, and pH. Shape-memory gels (SMGs) are kind of smart material that have the ability to demonstrate reversible shape transfor...

Previously our group has developed poly(dimethyl acrylamide-co-stearyl acrylate (DMAAm-co-SA) based shape memory gels (SMG) [1] with high mechanical strength, very good transparency and biocompatibility having potential application in different sectors [2]. Most commonly used polymers in order to fabricate sensor skins is Polydimethylsiloxane (PDMS...

A vast majority of IoT sensor devices use silicon-based sensors. However, with the development of state-of-the-art soft elastomeric microelectromechanical systems (MEMS) technology, flexible shape conformable sensors are now possible [1]. This unlocks an entirely new set of IoT-enabled products. Due to their thin, lightweight, and over all superior...

Ionic liquied mediated gels commonly known as ion gels or ionic gels have received remarkable attention for their advanced application in electrochemical and electromechanical devices, such as actuators, lithium batteries, electric double-layer capacitors, dye-sensitized solar cells and fuel cells [1, 2]. Investigation of the internal structure of...

Polymer monoliths composed with macroporous sizes are one of the potential candidates in separation technology and for efficient and stable separators in batteries and fuel cells [1]. Recently, thiol-ene "click" reaction has been received extensive attention in the field of monolith preparation owing to its exceptional versatility and propensity fo...

The aim of developing a multi-material 3D printer is to print an object with a different kind of soft and hard material in a single run. It is expected that the combination of printing soft and hard material will be a new kind of 3D printer. The main printing material for this printer is the conductive based soft filament made by our laboratory “So...

Hydrogels having shape memory behavior are one of the smart materials with numerous possible application in sensor, optical and biomedical field. Thermo-responsive gels have the ability to show reversible shape transformation due to the melting induced order-disordered transitions of the molecular constituent. Our group has developed poly(dimethyl...

The polymer gel is composed of polymeric chains which are crosslinked in a three-dimensional (3D) network structure and liquid which is widely applied to tissue engineering, medical treatment, and solid state electrochemical devices. The gel contains a large amount of water inside the three-dimensional network structure. The human body is also most...

Understanding the internal structure of the gels is important to comprehend their physico-chemical properties and propose better utilization in practical application. The scanning microscopic light scattering (SMILS) is one of the powerful tools to nondestructively characterize the internal structure of gels. The SMILS is a typical dynamic light sc...

Utilization of soft material like hydrogels for task-specific applications such as in soft robotics requires freedom in the manufacturing process and designability. Here, we have developed highly robust thermoresponsive poly(dimethyl acrylamide-co-stearyl acrylate and/or lauryl acrylate) (PDMAAm-co-SA and/or LA)-based shape memory gels (SMGs) using...

3D printing is getting remarkable consideration in recent years in miscellaneous areas and being focused in many hi-tech future possibilities in engineering 1,2 . 3D printable conductive polymer composites are gaining massive interest due to their impending application in the field of robotics, tactile, optical displays, microelectrochemical system...

Previously our group has developed poly(dimethyl acrylamide-co-stearyl acrylate (DMAAm-co-SA) based shape memory gels (SMG) [1] with high mechanical strength, very good transparency and biocompatibility having potential application in different sectors [2]. Most commonly used polymers in order to fabricate sensor skins is Polydimethylsiloxane (PDMS...

Polydimethylsiloxane (PDMS), a silicone based thermosetting elastomer, has been widely used because of its biocompatibility, low cost, low toxicity, high oxidative and thermal stability, optical transparent, low permeability to water, low electrical conductivity, and ease of micropatterning [1, 2]. Various nanocomposites have been fabricated employ...

Hydrogels having shape memory behavior are one of the smart materials with numerous possible application in sensor, optical and biomedical field. Thermo-responsive gels have the ability to show reversible shape transformation due to the melting induced order-disordered transitions of the molecular constituent. Our group has developed poly(dimethyl...

The aim of developing a multi-material 3D printer is to print an object with a different kind of soft and hard material in a single run. It is expected that the combination of printing soft and hard material will be a new kind of 3D printer. The main printing material for this printer is the conductive based soft filament made by our laboratory “So...

Ionic liquied mediated gels commonly known as ion gels or ionic gels have received remarkable attention for their advanced application in electrochemical and electromechanical devices, such as actuators, lithium batteries, electric double-layer capacitors, dye-sensitized solar cells and fuel cells [1, 2]. Investigation of the internal structure of...

Understanding the internal structure of the gels is important to comprehend their physico-chemical properties and propose better utilization in practical application. The scanning microscopic light scattering (SMILS) is one of the powerful tools to nondestructively characterize the internal structure of gels. The SMILS is a typical dynamic light sc...

Hydrogels are capable of absorbing large amounts of liquid or biological fluids in three-dimensional polymeric networks. The properties of smart gels can be controlled or tuned by external stimuli such as heat, optics, solvent, and pH. Shape-memory gels (SMGs) are kind of smart material that have the ability to demonstrate reversible shape transfor...

A vast majority of IoT sensor devices use silicon-based sensors. However, with the development of state-of-the-art soft elastomeric microelectromechanical systems (MEMS) technology, flexible shape conformable sensors are now possible [1]. This unlocks an entirely new set of IoT-enabled products. Due to their thin, lightweight, and over all superior...

The transport of liquid in the polymeric network of Hydrogels have been discussed for a decade because the gel membrane may use as chemical separator [1]. Here we demonstrate a system that control the flux of solvents by a combination of three types of gels of different swelling behavior as a gel transistor. Poly(dimethyl acrylamide-co-stearyl acry...

Polymer monoliths composed with macroporous sizes are one of the potential candidates in separation technology and for efficient and stable separators in batteries and fuel cells [1]. Recently, thiol-ene "click" reaction has been received extensive attention in the field of monolith preparation owing to its exceptional versatility and propensity fo...

The polymer gel is composed of polymeric chains which are crosslinked in a three-dimensional (3D) network structure and liquid which is widely applied to tissue engineering, medical treatment, and solid state electrochemical devices. The gel contains a large amount of water inside the three-dimensional network structure. The human body is also most...

Various kind of gel materials for example tough double network hydrogels [1], shape memory hydrogels [2] and ionic gels [3] have been developed with potential in numerous sectors. The transparent, flexible and low friction properties of these gels have added different prospects in scientific and technological areas. Utilization of 3D printing in fa...

In this work we have combined the physical and mechanical properties of the thermo-responsive poly (N,N-dimethyl acrylamide-co-Stearyl acrylate) (PDMAAm-co-SA) shape memory gels (SMGs) with the electrical activity of an electroactive component in order to develop a hybrid material named conductive SMG (C-SMG) that can sense their shape transformati...

Shape memory gels (SMGs) are one of the interesting and unique classes of soft and wet materials having wide application in actuator, sensor, optical and biomedical field. Thermal responsive SMGs have the ability to return from a temporary deformed state to its original shape under the influence of heat thus having the limitation of quick and prope...

Hydrogels possess three-dimensional polymeric networks and capable of absorbing large amounts of water or biological fluids. Due to their high water content, porosity and low friction they closely simulate natural living tissue. The properties of a polymer gel depend on the chemical structures of the component molecule and can be controlled or tune...

Hydrogels possess three-dimensional polymeric networks and capable of absorbing large amounts of water or biological fluids. Due to their high water content, porosity and low friction they closely simulate natural living tissue. The properties of a polymer gel depend on the chemical structures of the component molecule and can be controlled or tune...

Shape memory gels (SMGs) are one of the interesting and unique classes of soft and wet materials having wide application in actuator, sensor, optical and biomedical field. Thermal responsive SMGs have the ability to return from a temporary deformed state to its original shape under the influence of heat thus having the limitation of quick and prope...

Polymeric superabsorbent hydrogels are the kind of gels that are obtained by chemically synthesizing with hydrophilic polymers to form a 3D-network structure. These hydrogels have been extensively used in agriculture over the last two decades as an absorbent. The aim of this work is to use the polymeric hydrogel to increase the water holding proper...

Gels have three-dimensional cross-linked polymer network, which can extensively swell in water or hydrophilic solvents depending on their structure. High swelling property of the hydrogels can be very beneficial to use them as electrolyte material for battery application. Among the energy storage devices like lithium-ion, nickel-cadmium, and lead-a...

This paper describes fabrication of complex 3-D printed Polymer MEMS Devices. Since geometric complexity is not a concern for 3-D printing, complex 3D microfluidics, MEMS and lab-on-a-chip devices can be easily fabricated that are otherwise time consuming and difficult to manufacture with state of the art 2-D MEMS fabrication technology. Furthermor...

Polymeric superabsorbent hydrogels are a kind of gels, obtained by chemically synthesized with hydrophilic polymers in a form of 3D-network structure. This hydrogels have been extensively used in agriculture over the last two decades as an absorbent. The aim of this work is to use the polymeric hydrogel for increasing the water holding properties o...

In microfabricated MEMS actuator, sensor and biomedical devices, soft polymeric materials like silicone and nylon are widely used for their light weight, low cost, high corrosion resistance, high electrical resistance, high flexibility and high dimensional stability. Along with their numerous beneficial functions these materials have some shortcomi...

A polymeric super absorbent hydrogels are a kind of gels, obtained by chemically synthesized with hydrophilic polymers in a form of 3D-network structure. This hydrogels have been extensively used in agriculture over the last two decades as an absorbent. The aim of this work is to use the polymeric hydrogel for increasing the water holding propertie...

This paper describes fabrication of complex 3-D printed Polymer MEMS Devices. Since geometric complexity is not a concern for 3-D printing, complex 3D microfluidics, MEMS and lab-on-a-chip devices can be easily fabricated that are otherwise time consuming and difficult to manufacture with state of the art 2-D MEMS fabrication technology. Furthermor...

Gels have three-dimensional cross-linked polymer network, which can extensively swell in water or hydrophilic solvents depending on their structure. High swelling property of the hydrogels can be very beneficial to use them as electrolyte material for battery application. Among the energy storage devices like lithium-ion, nickel-cadmium, and lead-a...

Ionic gels (IGs) using ionic liquids (ILs) can propose diverse applications in the field of optics, sensors and separation have opened wide prospects in materials science. ILs have attracted remarkable interest for gel polymer electrolytes and batteries based on their useful properties such as non-volatility, non-flammability, a wide electrochemica...

Gels are an important class of soft and wet materials having superior properties with diverse applications in tissue engineering, bio-medical engineering, and electrochemistry. In order to accelerate the development of gels, it is required to synthesize multi-functional gels of high mechanical strength, ultra low surface friction and suitable elast...

Gels are a promising class of soft and wet materials with diverse application in tissue engineering and bio-medical purpose. In order to accelerate the development of gels, it is required to synthesize multi-functional gels of high mechanical strength, ultra low surface friction and suitable elastic modulus with a variety of methods and new materia...

The shape memory hydrogels were synthesized and studied the physical properties. The gels were made by a hydrophilic monomer named N, N-dimethyl acrylamide (DMAAm) and a hydrophobic monomer named stearyl acrylate (SA). The water-swollen hydrogels show well transparency and shape memory property while gels absorb large water content. The properties...

Polarity behavior of a hydrophobic ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulphonylimide [EMI][TFSI] and binary mixtures of [EMI][TFSI] with ethanol, acetone and dichloromethane was investigated by solvatochromic method using Reichardt's betaine dye. Fluorescence spectroscopic method using pyrene as a probe was also used...

Polarity behavior of a hydrophobic ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulphonylimide [EMI][TFSI] and binary mixtures of [EMI][TFSI] with ethanol, acetone and dichloromethane was investigated by solvatochromic method using Reichardt’s betaine dye. Fluorescence spectroscopic method using pyrene as a probe was also used...