Page 357 - IJB-9-5

International Journal of Bioprinting 3D printing of tough and self-healing hydrogels

Figure 4. Electrically conductive hydrogel inks. (A) Schematic illustration of the synthesis process of PVA/TA/PAA/CNT hydrogel inks. (B) Stress–strain
curves of PVA/TA/PAA/CNT hydrogel with varying CNT concentration. (C) Conductivity as a function of CNT concentration. (D) Schematic illustration
of tissue adhesive property of the hydrogel treated with NHS. (E) Photographs of PVA/TA/PAA/CNT hydrogel adhesion on porcine skin. (F) Fluorescent
images of in vitro biocompatibility test after 1, 3, and 5 days. (G) The percentage of cell viability of in vitro biocompatibility test of the hydrogel (ns: no
significant differences; n = 3; n is the sample size for each group).

CNT hydrogel ink, the conductivity of these hydrogel inks at 6 mg/mL showed the most balanced characteristics, which
CNT concentrations of 1, 3, 6, and 9 mg/mL was measured have high conductivity with good mechanical properties,
to determine whether the conductivity is sufficient to further experiments were conducted with PVA/TA /PAA/
1:1
sense electrophysiological signals from the human body CNT hydrogels with the CNT concentration of 6 mg/mL.
(Figure 4C). The results showed a conductivity of ~0.95 S/m 3.7. Tissue adhesion and in vitro
at CNT concentration of 6 mg/mL, which is sufficient, biocompatibility tests
given that the conductivity of human tissue is in the Conformal contact between tissue and electric devices is
range of 0.3–0.7 S/m . Since the CNT concentration of required for the stable and efficient operation of body signal
[43]

Volume 9 Issue 5 (2023) 349 https://doi.org/10.18063/ijb.765