title: Direct Pen Writing of Adhesive Particle-Free Ultrahigh Silver Salt-Loaded Composite Ink for Stretchable Circuits.
abstract: In this article, we describe a writable particle-free ink for fast fabrication of highly conductive stretchable circuits. The composite ink mainly consists of soluble silver salt and adhesive rubber. Low toxic ketone was employed as the main solvent. Attributed to ultrahigh solubility of silver salt in short-chain ketone and salt-assisted dissolution of rubber, the ink can be prepared into particle-free transparent solution. As-prepared ink has a good chemical stability and can be directly filled into ballpoint pens and use to write on different substrates to form well adhesive silver salt-based composite written traces as needed. As a result of high silver salt loading, the trace can be converted into highly conductive silver nanoparticle-based composites after in situ reduction. Because of the introduction of adhesive elastomeric rubber, the as-formed conductive composite written trace can not only maintain good adhesion to various substrates but also show good conductivity under various deformations. The conductivity of written traces can be enhanced by repeated writing-reduction cycles. Different patterns can be fabricated by either direct handwriting or hand-copying. As proof-of-concept demonstrations, a typical handwriting heart-like circuit was fabricated to show its capability to work under different deformations, and a pressure-sensitive switch was also manufactured to present pressure-dependent change of resistance.
authors.affiliation: Department of Mechanical and Materials Engineering, The University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Mingjun
authors.initials: M
authors.lastname: Hu
authors.affiliation: Department of Mechanical and Materials Engineering, The University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Cai
authors.affiliation: Department of Mechanical and Materials Engineering, The University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Qiuquan
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Mechanical and Materials Engineering, The University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Bin
authors.initials: B
authors.lastname: Bian
authors.affiliation: Department of Mechanical and Materials Engineering, The University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Tengyuan
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Mechanical and Materials Engineering, The University of Western Ontario , London, Ontario N6A 5B9, Canada.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
keywords: elastomeric conductor; flexible and stretchable electronics; printed electronics; silver nanoparticles; writable and printable ink