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 vol. 5 p. 2184 - 2184

onic gels from eutectic mixtures are attracting extensive interest in bioelectronics owing to their nonvolatile nature, low cost, and inherently high ionic conductivity. Biodegradable electronics made of biopolymers envisage a promising future in this field, but unfortunately, they often feature poor mechanics. Herein, we explored tannic acid-decorated cellulose nanocrystals (TA@CNC) as dynamic nanofillers of biocompatible eutectogels based on gelatin and a eutectic mixture composed of choline chloride and ethylene glycol (ethaline). Small concentrations of TA@CNC (up to 1-2 wt %) allow increasing by two-fold the strength (30 kPa) and stretchability (180%) of the eutectogels while improving their ionic conductivity (105 mS·m-1). The reversible physical network of the protein and multiple hydrogen bonding interactions with tannic acid endow these eutectogels with good self-adhesiveness, suitable gel-to-sol transition for 3D printing, and recyclability. We further used the cellulose nan