@article {47357,
	title = {Elastic piezoelectric aerogels from isotropic and directionally ice-templated cellulose nanocrystals: comparison of structure and energy harvesting},
	journal = {Cellulose},
	volume = {28},
	year = {2021},
	month = {JUL},
	pages = {6323-6337},
	type = {Article},
	abstract = {<p>We report the preparation of highly compressible and elastic piezoelectric aerogels of carboxylated cellulose nanocrystals (CNCs). Aqueous CNC dispersions containing polyethyleneimine and crosslinker were frozen isotropically to yield isotropic aerogels, while oriented aerogels were prepared by directional freezing. These aerogels were highly flexible and porous (similar to 85\% void fraction), exhibiting greater than 90\% recovery at 50\% compressive strain even after 100 compression-decompression cycles. Since such aerogels with low bulk modulus and high anisotropy would be an ideal platform for leveraging the piezoelectric properties of CNCs, we used them to prepare piezoelectric nanogenerator devices and determined their energy transduction behavior. Anisotropic aerogels led to an enhanced open-circuit voltage of 840 mV (at similar to 8 N applied force), which is over 2.6 times higher than isotropic aerogels (320 mV). The energy density of anisotropic aerogels was around 52 nW/cm(2), representing outstanding piezoelectric performance for cellulose-based aerogels. Such aerogels with high compressibility, elastic recovery and exceptional piezoelectric performance could have potential applications in sensors, wearable electronics, etc.</p>},
	keywords = {Aerogel, Anisotropic, Cellulose nanocrystals, energy harvesting, Piezoelectricity},
	issn = {0969-0239},
	doi = {10.1007/s10570-021-03896-6, Early Access Date = MAY 2021},
	author = {Ram, Farsa and Biswas, Bipul and Torris, Arun and Kumaraswamy, Guruswamy and Shanmuganathan, Kadhiravan}
}
@article {49069,
	title = {Highly electrostrictive salt cocrystal and the piezoelectric nanogenerator application of its 3D-printed polymer composite},
	journal = {ACS Applied Materials and Interfaces },
	volume = {16},
	year = {2024},
	month = {MAY},
	pages = {26406-26416},
	type = {Article},
	abstract = {<p>
	Ionic cocrystals with hydrogen bonding can form exciting materials with enhanced optical and electronic properties. We present a highly moisture-stable ammonium salt cocrystal [CH3C6H4CH(CH3)NH2][CH3C6H4CH(CH3)NH3][PF6] ((p-TEA)(p-TEAH)PF6) crystallizing in the polar monoclinic C2 space group. The asymmetry in (p-TEA)(p-TEAH)PF6 was induced by its chiral substituents, while the polar order and structural stability were achieved by using the octahedral PF6- anion and the consequent formation of salt cocrystal. The ferroelectric properties of (p-TEA)(p-TEAH)PF6 were confirmed through P-E loop measurements. Piezoresponse force microscopy (PFM) enabled the visualization of its domain structure with characteristic {\textquoteleft}{\textquoteleft}butterfly{\textquoteright}{\textquoteright} and hysteresis loops associated with ferro- and piezoelectric properties. Notably, (p-TEA)(p-TEAH)PF6 exhibits a large electrostrictive coefficient (Q(33)) value of 2.02 m(4) C-2, higher than those found for ceramic-based materials and comparable to that of polyvinylidene difluoride. Furthermore, the composite films of (p-TEA)(p-TEAH)PF6 with polycaprolactone (PCL) polymer and its gyroid-shaped 3D-printed composite scaled-up device, 3DP-Gy, were prepared and evaluated for piezoelectric energy-harvesting functionality. A high output voltage of 22.8 V and a power density of 118.5 mu W cm(-3) have been recorded for the 3DP-Gy device. Remarkably, no loss in voltage outputs was observed for the (p-TEA)(p-TEAH)PF6 devices even after exposure to 99\% relative humidity, showcasing their utility under extremely humid conditions.</p>
},
	keywords = {3D printing, cocrystals, energy harvesting, ferroelectricity, Piezoelectricity},
	issn = {1944-8244},
	doi = {10.1021/acsami.4c03349},
	author = {Sahoo, Supriya and Panday, Rishukumar and Kothavade, Premkumar and Sharma, Vijay Bhan and Sowmiyanarayanan, Anirudh and Praveenkumar, Balu and Zareba, Jan K. and Kabra, Dinesh and Shanmuganathan, Kadhiravan and Boomishankar, Ramamoorthy}
}
