@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}
}
@article {49901,
	title = {Highly moisture-stable ferroelectric ammonium phosphate salt showing piezoelectric energy harvesting and rotation sensing applications},
	journal = {Journal of Materials Chemistry A},
	volume = {13},
	year = {2025},
	month = {JUL},
	pages = {22574-22582},
	type = {Article},
	abstract = {<p>
	Ferroelectric phosphate-based materials are known for their biocompatibility, dipole switching, and high thermal stability. In this context, we report a novel organic ferroelectric material, diisopropylammonium bis(4-nitrophenyl) phosphate (DIPABNPP), crystallizing in the monoclinic C2 space group. DIPABNPP exhibits a high second harmonic generation (SHG) efficiency 2.5 times higher than that of potassium dihydrogen phosphate (KDP). The ferroelectric nature of DIPABNPP was confirmed by the observation of a rectangular P-E hysteresis loop, which gave a saturated polarization value of 6.82 mu C cm-2. The ferroelectric polar domains of DIPABNPP, along with the bias-dependent amplitude butterfly and phase hysteresis loops, were visualized by piezoresponse force microscopy (PFM). Furthermore, the polydimethyl siloxane (PDMS) composites of DIPABNPP enabled the fabrication of humidity-resistant piezoelectric nanogenerators (PENGs) with energy harvesting and mechanical-electrical sensing capabilities. The top-performing 10 wt\% DIPABNPP-PDMS device achieved a peak output voltage of 9.5 V and a charge storage efficiency of 81.8\%, successfully powering 53 LEDs. Additionally, its rapid response time of 18.5 ms enables precise rotation sensing capabilities, suggesting potential applications in motion monitoring, such as revolution per minute (RPM) counting. We also present a unique and refined method for obtaining the output work efficiency (OWE) parameter, which quantifies the ratio of harvested electrical energy to the maximum elastic energy stored in the composite device, taking into consideration several key parameters during the PENG measurements. For the 10 wt\% DIPABNPP-PDMS composite, an OWE of 13.1\% was achieved, highlighting both its current performance and potential for optimization. This metric provides a standardized approach for evaluating PENGs, addressing a critical gap in assessing mechanical-to-electrical energy conversion efficiency.</p>
},
	issn = {2050-7488},
	doi = {10.1039/d5ta01846c},
	author = {Kushwaha, Vikash and Prajesh, Neetu and Gopal, Animesh and Sahoo, Supriya and Deswal, Swati and Kirana, Antonysylvester and Shanmuganathan, Kadhiravan and Zareba, Jan K. and Boomishankar, Ramamoorthy}
}
