Isotropic conductive paste for bioresorbable electronics

Kyung Su Kim; Woo-Youl Maeng; Seongchan Kim; Gyubok Lee; Minki Hong; Ga-Been Kim; Jaewon Kim; Sungeun Kim; Seunghun Han; Jaeyoung Yoo; Hyojin Lee; Kangwon Lee; Jahyun Koo

doi:10.1016/j.mtbio.2023.100541

Isotropic conductive paste for bioresorbable electronics

Mater Today Bio. 2023 Jan 4:18:100541. doi: 10.1016/j.mtbio.2023.100541. eCollection 2023 Feb.

Authors

Kyung Su Kim^{1

2}, Woo-Youl Maeng³, Seongchan Kim⁴, Gyubok Lee⁵, Minki Hong^{1

2}, Ga-Been Kim^{1

4}, Jaewon Kim¹, Sungeun Kim^{1

2}, Seunghun Han^{1

2}, Jaeyoung Yoo⁶, Hyojin Lee^{4

7}, Kangwon Lee^{5

8}, Jahyun Koo^{1

2}

Affiliations

¹ School of Biomedical Engineering, Korea University, Seoul, 02841, South Korea.
² Interdisciplinary Program in Precision Public Health, Korea University, Seoul, 02841, South Korea.
³ Center for Bio-Integrated Electronics, Northwestern University, Evanston, IL, 60208, USA.
⁴ Biomaterials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, South Korea.
⁵ Department of Applied Bioengineering, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, 08826, South Korea.
⁶ Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.
⁷ Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology (UST), Seoul, 02792, South Korea.
⁸ Research Institute for Convergence Science, Seoul National University, Seoul, 08826, South Korea.

Abstract

Bioresorbable implantable medical devices can be employed in versatile clinical scenarios that burden patients with complications and surgical removal of conventional devices. However, a shortage of suitable electricalinterconnection materials limits the development of bioresorbable electronic systems. Therefore, this study highlights a highly conductive, naturally resorbable paste exhibiting enhanced electrical conductivity and mechanical stability that can solve the existing problems of bioresorbable interconnections. Multifaceted experiments on electrical and physical properties were used to optimize the composition of pastes containing beeswax, submicron tungstenparticles, and glycofurol. These pastes embody isotropic conductive paths for three-dimensional interconnects and function as antennas, sensors, and contact pads for bioresorbable electronic devices. The degradation behavior in aqueous solutions was used to assess its stability and ability to retain electrical conductance (∼7 kS/m) and structural form over the requisite dissolution period. In vitro and in vivo biocompatibility tests clarified the safety of the paste as an implantable material.

Keywords: Biodegradable electronics; Conductive paste; Implantable medical device; Isotropic conductive adhesive; Screen printing.