Fig. 1. Nanojoint of Ag nanowires obtained by different nanowelding methods. (a) Femtosecond laser induced nanowelding^[23-25]; (b) irradiation by halogen tungsten lamps^[16]; (c) low temperature pressure welding^[27]; (d) Joule heating jointing^[12]; (e) high temperature annealing^[11]

Fig. 2. Electrical performance test of nano interconnection. (a) Two-point contact measurement based on nanometer operation probe^[33]; (b) integrated measurement based on MEMS and scanning electron microscopy^[34-35]

Fig. 3. Mechanical performance test of nano-interconnect structure. (a)(b) Measurement method based on AFM and optical microscope^[38,45]; (c) MEMS-assisted measurement^[46]; (d) measurement based on TEM-SEM chip^[47-48]; (e) TEM-AFM in-situ integrated measurement^[26]

Fig. 4. Ag-Ag local plasma welding induced by continuous laser^[56]. (a)-(d) In-situ welding of Ag nanowire gaps; (e) electrical properties of Ag nanowires before and after cutting and after nanoheating; (f) electrical properties of lap Ag nanowire before and after nanosoldering

Fig. 5. Nano interconnection of heterogeneous metals. (a) Three-dimensional arch bridge structure with continous laser-induced connection of Ag nanowires and Au electrodes and its electrical/ mechanical properties^[57]; (b) ultrathin Ag-Au nanowires cold welding^[7]; (c) cold welding of ultra-thin Cu-Al nanowires^[58]

Fig. 6. Laser-induced nanowelding between ZnO and Ag nanowires^[59]. (a) Schematic; (b) morphology of single welded junction; (c) temperature distribution of nanowire; (d) welding image of ZnO and Au electrodes; (e) I-V (current-voltage) curves before and after welding; (f) semilog plot of current-voltage characteristic curve

Fig. 7. Laser-induced nanowelding between metal electrodes and semiconductor nanomaterials. (a)-(d) Femtosecond laser-induced Au/SiO₂/SiC heterogeneous nanojoint and electrical characteristics of three-terminal devices^[61]; (e)(f) laser-induced heterogeneous nanojoint between metal electrodes and graphene and its photoelectric performance^[63]

Fig. 8. Electrical/mechanical properties of flexible interconnected thin films welded by laser plasma^[71]. (a) Fatigue resistance test of Cu nanowires; (b) laser induced long Ag nanowires interconnection and its electrical/mechanical performance testing

Fig. 9. Electrical/mechanical performance of thin films based on metal nanowelding networks. (a)-(c) Laser-induced flexible mesh structure based on Cu nanoparticles^[74]; (d) stripping testing of interconnected Ag nanowires and flexible substrate^[73]

Fig. 10. Electrical/mechanical performance of thin films based on interconnection networks of carbon-based nanomaterials. (a)(b) Laser-induced nanowelding between CNTs and flexible substrate and mechanics properties testing^[79]; (c) laser-induced carbon nanotubes interconnect with metal electrodes^[64]; (d) laser-induced carbon nanotubes interconnection network^[81]

Fig. 11. Electrical/mechanical performance of semiconductor interconnect structures. (a) Femtosecond laser-induced nanowelding between ZnO nanowires and its photoelectrical response^[23]; (b) laser-induced interconnection of ZnO and GaN thin films and electroluminescence enhancement of the device after interconnection^[84]