Fabrication of a new type of electrically conductive micro-tracks via mechanical compression of beaded structures

• Uniaxial mechanical compression enables fabrication of conductive micro-tracks with high height-to-width ( h : w ) aspect ratios • Numerical COMSOL simulations are used to evaluate shape evolution and resistance changes in particle chains. • Polydispersity has minor effect on R ( ε ) relationship, but reduces resistance at low strain due to faster contact area growth. • The presence of liquid between microparticles in the chain promotes a faster reduction in resistance at low strain levels. • Optimal structural compression ( ε = 48%, h : w= 1:2.5) yields maximal conductivity and minimal shading in PV applications. In recent years, the importance of critical raw materials for global economic development has become increasingly evident, especially in electronics. A challenge in this industry is replacing traditional, unsustainable silver nanoparticle-based conductive pastes used for creating conductive paths. This paper presents an approach to fabricating conductive micro-tracks from preassembled bead-like chains of microparticles. These single-particle-thick structures achieve high conductivity through a straightforward post-processing method — mechanical compression — offering a sustainable alternative to complex nanoparticle pastes. Our study explores the effects of uniaxial compression on malleable microparticles deposited additively on substrates, examining particle deformation, interparticle contact area changes, and their impact on conductivity. Through comprehensive numerical simulations, closely aligned with experimental observations, we establish a quantitative relationship between compressive strain ( ε ), compressive force ( F N ), the contact area between the compressing plate and the ball ( A 1 ), interparticle contact area ( A 2 ), and the electrical resistance ( R ) of the particle chain. We studied linear structures of monodisperse microparticles and investigated the effects of polydispersity and deviations from linearity. Furthermore, we studied the influence of compression force and process temperature on the stability of the substrate on which beaded structures are formed. This research presents a sustainable alternative to traditional nanoparticle pastes, offering a bottom-up method for developing optimized conductive paths.