Semiconductive hydrogels denote a strategically valuable platform associated with interdiscipline fields by double advantages of metals and organisms (eco‐friendliness, structural flexibility, mixed conduction, real‐time responsiveness, scalable fabrication, and chemical stability). Nevertheless, the orthodox chemical/physical methods processing hydrogels yield planar‐like layers or rough structures without ultrafine feature size or manipulative performance, falling short of µ‐robotics, µ‐electronics, or n‐energy industries. Thereby, scaling the device's volume down and unleashing material's potential become crucially important for broadband applications. A femtosecond laser lifting‐off technique is synthesized with self‐assembly to break conventional volume/resolution limitation, enlarge the geometry‐design capacity, and desirable electricity conduction for micro/nanosituations. Low‐dimensional high‐performance nanowires, electric circuits, ultrathin interdigital capacitors, manipulative photon filters, and metasurfaces are functionalized here. The repeated experiment concludes a high‐density integration ability with a subminiature size down to 10 × 10 × 0.02 µm3, tunable electric conductivity up to 1.17 × 105S m−1, and areal capacitance >16.2 mF cm−2for energy storage higher than those electrochemical double‐layer ones. Large geometry capacity with nanometric resolution provides access to future‐perspective optoelectronic products, n‐energy, bioneural recordings, or interfaces of embedding conditions.
Spatial manipulation of nanoparticles (NPs) in a controlled manner is critical for the fabrication of 3D hybrid materials with unique functions. However, traditional fabrication methods such as electron‐beam lithography and stereolithography are usually costly and time‐consuming, precluding their production on a large scale. Herein, for the first time the ultrafast laser direct writing is combined with external magnetic field (MF) to massively produce graphene‐coated ultrafine cobalt nanoparticles supported on 3D porous carbon using metal–organic framework crystals as precursors (5 × 5 cm2with 10 s). The MF‐confined picosecond laser scribing not only reduces the metal ions rapidly but also aligns the NPs in ultrafine and evenly distributed order (from 7.82 ± 2.37 to 3.80 ± 0.84 nm). ≈400% increment of N‐Q species within N compositionis also found as the result of the special MF‐induced laser plasma plume. (). The importance of MF is further exmined by electrochemical water‐splitting tests. Significant overpotential improvements of 90 and 150 mV for oxygen evolution reaction and hydrogen evolution reaction are observed, respectively, owing to the MF‐induced alignment of the NPs and controlled elemental compositions. This work provides a general bottom‐up approach for the synthesis of metamaterials with high outputs yet a simple setup.
more » « less- PAR ID:
- 10366417
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Science
- Volume:
- 8
- Issue:
- 24
- ISSN:
- 2198-3844
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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