Accelerable Self-Sintering of Solvent-Free Molybdenum/Wax Biodegradable Composites for Multimodally Transient Electronics

Biodegradable conductive composites are key materials
or components
for printable transient electronics that can be fabricated in a low-cost
and high-efficiency manner, thereby boosting their wide applications
in biomedical engineering, hardware security, and environmental-friendly
electronics. Continuous efforts in this area still lie in the development
of strategies for highly conductive, safe, and reliable biodegradable
conductive composite materials and devices. This paper introduces
molybdenum/wax composites for multimodally printable transient electronics
in which multiple transience modes including dissolution-induced degradation
and thermally triggered degradation are available. Systematic experiments
demonstrate several advantages and unique properties of this material
system, including solvent-free fabrication, self-sintering behavior,
and long-term and high conductivity via accelerable self-sintering
treatment and rehealing capabilities. Notably, the immersion of molybdenum/wax
composites in phosphate buffer solution can provide both positive
effects (accelerated self-sintering-dominated) and negative effects
(degradation-dominated) on their electrical conductivities. Mechanism
analyses reveal the basis for balancing the degradation and accelerated
self-sintering processes. The presented demonstrations foreshadow
opportunities of the developed molybdenum/wax composites in rehealable
electronics, on-demand smart transient electronics with multiple transience
modes, and many other related unusual applications.