A new nanowire fabrication technique yields flexible electronics virtually impervious to electromagnetic interference. The process devised at the University of Glasgow, Scotland, offers an efficient approach for interfacial imprinting ultra-thin nanowires onto bendable, transparent polymeric substrates.
The interfacial-dielectrophoresis (i-DEP) process uses electrical fields to arrange nanoscale materials with high accuracy, enabling the creation of precise patterns. Gaps formed in the nanowire network serve as capacitors, reducing the potential for external signals to affect internal electronics and creating what the researchers term a capacitively-coupled interwire network.
During a subsequent laser processing stage, ultrafast pulses of picosecond light bond junctions between silver nanowires together to support electrical interconnections. The process also strips the coating of insulating material from nanowires, increasing optical transparency by up to 10% and reducing electrical resistance by a factor of 46.
Test results reported in ACS Nano confirm extreme resilience to electronic interference, achieving more than 35 decibels of shielding effectiveness across the 2.2 GHz to 6 GHz frequency band. This allowed the flexible electronics to block more than 99.97% of incident electromagnetic radiation while maintaining 83% optical transparency.
According to the researchers, the new technique also provides a solution for key manufacturing challenges. Unlike conventional cleanroom fabrication, the i-DEP technology can produce larger materials, as demonstrated by the manufacture of devices measuring 40 cm by 80 cm.
