3 research outputs found
Direct foam writing in microgravity
Herein we report 2D printing in microgravity of aqueous-based foams containing metal oxide nanoparticles. Such hierarchical foams have potential space applications, for example for in situ habitat repair work, or for UV shielding. Foam line patterns of a TiO2-containing foam have been printed onto glass substrates via Direct Foam Writing (DFW) under microgravity conditions through a parabolic aircraft flight. Initial characterization of the foam properties (printed foam line width, bubble size, etc.) are presented. It has been found that gravity plays a significant role in the process of direct foam writing. The foam spread less over the substrate when deposited in microgravity as compared to Earth gravity. This had a direct impact on the cross-sectional area and surface roughness of the printed lines. Additionally, the contact angle of deionized water on a film exposed to microgravity was higher than that of a film not exposed to microgravity, due to the increased surface roughness of films exposed to microgravity
Versatile Interpenetrating Polymer Network Approach to Robust Stretchable Electronic Devices
The
pursuit of intelligent optoelectronics could have profound
implications on our future daily life. Simultaneous enhancement of
the electrical performance, mechanical stretchability, and optical
transparency of semiconducting polymers may significantly broaden
the spectrum of realizable applications for these materials in future
intelligent optoelectronics, i.e., wearable devices, electronic skin,
stretchable displays, and a vast array of biomedical sensors. Here,
semiconducting films with significantly improved mechanical elasticity
and optical transparency, without affecting the film’s electronic
conductivity even under 100% strain, were prepared by blending only
a small amount (below 1 wt %) of either p-type or n-type commercial
semiconductor polymers. We demonstrate that a self-organized versatile
conjugated polymer film displaying an interpenetrating polymer network
is formed in the semiconducting films and is crucial for the observed
enhancement of elasticity, optical transparency, and charge-carrier
mobility. On the basis of this versatile semiconducting film, we explored
a new practical approach to directly integrate all the stretchable
components for a large area transistor array through solution processing
and a final single, mechanical peel-off step. We demonstrate robust
transistor arrays exhibiting charge carrier mobilities above 1.0 cm<sup>2</sup>/V s with excellent durability, even under 100% strain. We
believe our achievements will have great impact on stretchable optoelectronic
devices for practical applications and represent promising directions
for industry-scale production of stretchable displays and wearable
electronic devices