@article {46648, title = {Ultrahigh sensitive carbon-based conducting rubbers for flexible and wearable human-machine intelligence sensing}, journal = {Advanced Materials Technologies}, volume = {5}, year = {2020}, month = {DEC}, pages = {2000690}, type = {Article}, abstract = {

The wearable strain sensors with multifunctional applications can fuel the rapid development of human-machine intelligence for various sectors like healthcare, soft robotics, and Internet of Things applications. However, achieving the low-cost and mass production of wearable sensors with ultra-high performance remains challenging. Herein, a simple, cost-effective, and scalable methodology to fabricate the flexible and highly sensitive strain sensors using carbon black and latex rubbers (LR) is presented. The LR-based strain sensor demonstrates excellent flexibility, fast response (approximate to 600 ms), ultra-high sensitivity (maximum gauge factor of 1.2 x 10(4) at 250\% strain), and long-term stability over 1000 cycles. The LR-based strain sensors are sensitive to monitor subtle human motions such as heart pulse rate and voice recognition along with high-strain human joint operations. Additionally, the sensing mechanism of LR bands is investigated by surface topographies and electromechanical response under various strained/unstrained conditions. Further, a smart glove-based sensor module made of LR strain bands with an Arduino reader for the human-machine intelligence device for non-verbal communication in military applications is demonstrated.

}, keywords = {conducting rubbers, gauge factor, human\&\#8211, machine interfacing, voice recognition, wearable strain sensors}, issn = {2365-709X}, doi = {10.1002/admt.202000690, Early Access Date = NOV 2020}, author = {Ajeev, Arya and Javaregowda, Bharathkumar H. and Ali, Ashik and Modak, Mrudul and Patil, Shreya and Khatua, Saumyakanta and Ramadoss, Marimuthu and Kothavade, Premkumar Anil and Arulraj, Arul Kashmir} } @article {48827, title = {3D-printed polymer composite devices based on a ferroelectric chiral ammonium salt for high-performance piezoelectric energy harvesting}, journal = {Materials Horizons}, volume = {10}, year = {2023}, month = {JUL}, pages = {3153-3161}, type = {Article}, abstract = {

Three-dimensional printing (3DP) is an emerging technology to fabricate complex architectures, necessary to realize state-of-the-art flexible and wearable electronic devices. In this regard, top-performing devices containing organic ferro- and piezoelectric compounds are desired to circumvent significant shortcomings of conventional piezoceramics, e.g. toxicity and high-temperature device processibility. Herein, we report on a 3D-printed composite of a chiral ferroelectric organic salt {[Me3CCH(Me)NH3][BF4]} (1) with a biodegradable polycaprolactone (PCL) polymer that serves as a highly efficient piezoelectric nanogenerator (PENG). The ferroelectric property of 1 originates from its polar tetragonal space group P4(2), verified by P-E loop measurements. The ferroelectric domain characteristics of 1 were further probed by piezoresponse force microscopy (PFM), which gave characteristic {\textquoteleft}butterfly{\textquoteright} and hysteresis loops. The PFM amplitude vs. drive voltage measurements gave a relatively high magnitude of the converse piezoelectric coefficient for 1. PCL polymer composites with various weight percentages (wt\%) of 1 were prepared and subjected to piezoelectric energy harvesting tests, which gave a maximum open-circuit voltage of 36.2 V and a power density of 48.1 mu W cm(-2) for the 10 wt\% 1-PCL champion device. Furthermore, a gyroid-shaped 3D-printed 10 wt\% 1-PCL composite was fabricated to test its practical utility, which gave an excellent output voltage of 41 V and a power density of 56.8 mu W cm(-2). These studies promise the potential of simple organic compounds for building PENG devices using advanced manufacturing technologies.

}, issn = {2051-6347}, doi = {10.1039/d3mh00444a}, author = {Sahoo, Supriya and Kothavade, Premkumar Anil and Naphade, Dipti R. and Torris, Arun and Praveenkumar, Balu and Zareba, Jan K. and Anthopoulos, Thomas D. and Shanmuganathan, Kadhiravan and Boomishankar, Ramamoorthy} } @article {48790, title = {Luminescent 3D printed poly(lactic acid) nanocomposites with enhanced mechanical properties}, journal = {Polymer Engineering and Science}, volume = {63}, year = {2023}, month = {JUL}, pages = {2059-2072}, type = {Article}, abstract = {

The three-dimensional (3D) printing of functional composite materials has gained tremendous interest in recent years. Nevertheless, research on 3D printing of luminescent composite materials is very limited, and the mechanical properties of such 3D-printed composites are poor. Herein, we report the preparation and characterization of a poly(lactic acid) (PLA) composite that, when 3D printed, exhibits enhanced toughness and high solid-state fluorescence quantum yield. Incorporation of only 1 wt\% pyrene butyric acid modified cellulose nanofibers (PBA-m-CNF) and l0 wt\% thermoplastic polyurethane (TPU) into PLA led to 223\% increase in toughness and 21\% increase in tensile modulus of PLA. Scanning electron microscopy (SEM) and X-ray microcomputed tomography (mu-CT) analysis of the fractured cross-sections of 3D printed composites revealed a ductile failure mode. The PLA/PBA-m-CNF1/TPU10 3D printed composite also exhibited a high solid-state fluorescence quantum yield of 38.35\%. To the best of our knowledge, this is the first report to show both enhanced mechanical properties and high solid-state fluorescence emission for 3D printable PLA. Such functional PLA composites could have potential applications in the fabrication of complex-shaped sensors, optical light pipes, etc.

}, keywords = {3D printing, Composite, fluorescence, Nanocellulose, poly(lactic acid), toughness}, issn = {0032-3888}, doi = {10.1002/pen.26345}, author = {Kothavade, Premkumar Anil and Yadav, Prashant and Nidhankar, Aakash D. and Torris, Arun and Pol, Harshawardhan and Kafi, Abdullah and Bateman, Stuart and Sukumaran, Santosh Babu and Shanmuganathan, Kadhiravan} }