Room Temperature Electrochemical Sintering of Zn Microparticles and Its Use in Printable Conducting Inks for Bioresorbable Electronics

Yoon Kyeung Lee; Jeonghyun Kim; Yerim Kim; Jean Won Kwak; Younghee Yoon; John A Rogers

doi:10.1002/adma.201702665

Room Temperature Electrochemical Sintering of Zn Microparticles and Its Use in Printable Conducting Inks for Bioresorbable Electronics

Adv Mater. 2017 Oct;29(38). doi: 10.1002/adma.201702665. Epub 2017 Aug 21.

Authors

Yoon Kyeung Lee^{1

2}, Jeonghyun Kim³, Yerim Kim², Jean Won Kwak², Younghee Yoon², John A Rogers⁴

Affiliations

¹ Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
² Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
³ Department of Electronics Convergence Engineering, Kwangwoon University, Seoul, 01897, Republic of Korea.
⁴ Center for Bio-Integrated Electronics, Departments of Materials Science and Engineering, Biomedical Engineering, Chemistry, Mechanical Engineering, Electrical Engineering and Computer Science, and Neurological Surgery, Simpson Querrey Institute for Nano/Biotechnology, McCormick School of Engineering, and Feinberg School of Medicine, Northwestern University, Evanston, IL, 60208, USA.

PMID: 28833596
DOI: 10.1002/adma.201702665

Abstract

This study describes a conductive ink formulation that exploits electrochemical sintering of Zn microparticles in aqueous solutions at room temperature. This material system has relevance to emerging classes of biologically and environmentally degradable electronic devices. The sintering process involves dissolution of a surface passivation layer of zinc oxide in CH₃ COOH/H₂ O and subsequent self-exchange of Zn and Zn²⁺ at the Zn/H₂ O interface. The chemical specificity associated with the Zn metal and the CH₃ COOH/H₂ O solution is critically important, as revealed by studies of other material combinations. The resulting electrochemistry establishes the basis for a remarkably simple procedure for printing highly conductive (3 × 10⁵ S m^-1 ) features in degradable materials at ambient conditions over large areas, with key advantages over strategies based on liquid phase (fusion) sintering that requires both oxide-free metal surfaces and high temperature conditions. Demonstrations include printed magnetic loop antennas for near-field communication devices.

Keywords: bioresorbable electronics; conductive inks; electrochemical sintering; printed electronics; transient electronics.