Natural, Biocompatible, and 3D-Printable Gelatin Eutectogels Reinforced with Tannic Acid-Coated Cellulose Nanocrystals for Sensitive Strain Sensors

MERCADAL, PABLO A.; ROMERO, MARCELO R.; MONTESINOS, MARIA DEL MAR; REAL, JUAN PABLO; PICCHIO, MATIAS L.; GONZÁLEZ, AGUSTÍN

ACS Applied Electronic Materials

American Chemical Society

Año: 2023

2637-6113

BSTRACT: Ionic gels from eutectic mixtures are attractingextensive interest in bioelectronics owing to their nonvolatilenature, low cost, and inherently high ionic conductivity.Biodegradable electronics made of biopolymers envisage apromising future in this field, but unfortunately, they often featurepoor mechanics. Herein, we explored tannic acid-decoratedcellulose nanocrystals (TA@CNC) as dynamic nanofillers ofbiocompatible eutectogels based on gelatin and a eutectic mixturecomposed of choline chloride and ethylene glycol (ethaline). Smallconcentrations of TA@CNC (up to 1−2 wt %) allow increasing bytwo-fold the strength (30 kPa) and stretchability (180%) of theeutectogels while improving their ionic conductivity (105 mS·m−1).The reversible physical network of the protein and multiplehydrogen bonding interactions with tannic acid endow these eutectogels with good self-adhesiveness, suitable gel-to-sol transition for3D printing, and recyclability. We further used the cellu