scholarly journals Direct Writing of Cu Patterns on Polydimethylsiloxane Substrates Using Femtosecond Laser Pulse-Induced Reduction of Glyoxylic Acid Copper Complex

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 493
Author(s):  
Nam Phuong Ha ◽  
Tomoji Ohishi ◽  
Mizue Mizoshiri

We investigate the direct writing properties of copper (Cu) patterns on glass and polydimethylsiloxane (PDMS) substrates using femtosecond laser pulse-induced thermochemical reduction of glyoxylic acid copper (GACu) complex. The films of the GACu complex coated on the substrates were irradiated by focused femtosecond laser pulses using a low numerical aperture of 0.45. Under the same conditions, such as laser scanning speed and pulse energy, the width of the line patterns fabricated on PDMS substrates was larger than that on glass substrates. X-ray diffraction peaks of the patterns on glass substrates corresponded to Cu without significant oxidation. By contrast, although Cu patterns were fabricated on PDMS substrates at a scanning speed of 10 mm/s and pulse energy of 0.49 nJ, Cu2O was also generated under overheating conditions at a scanning speed of 1 mm/s and pulse energy of 0.37 nJ. All the patterns exhibited electrical conductivity. The minimum resistivity of the patterns on PDMS substrates is 1.4 × 10−5 Ωm, which is 10 times higher than that on glass substrates, indicating that microcracks formed by thermal shrinkage of the substrates during the laser irradiation increase the resistivity. This direct Cu writing technique on soft materials is useful for fabricating flexible microdevices.

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 401 ◽  
Author(s):  
Mizue Mizoshiri ◽  
Keiko Aoyama ◽  
Akira Uetsuki ◽  
Tomoji Ohishi

We have fabricated Cu-based micropatterns in an ambient environment using femtosecond laser direct writing to reduce a glyoxylic acid Cu complex spin-coated onto a glass substrate. To do this, we scanned a train of focused femtosecond laser pulses over the complex film in air, following which the non-irradiated complex was removed by rinsing the substrates with ethanol. A minimum line width of 6.1 µm was obtained at a laser-pulse energy of 0.156 nJ and scanning speeds of 500 and 1000 µm/s. This line width is significantly smaller than that obtained in previous work using a CO2 laser. In addition, the lines are electrically conducting. However, the minimum resistivity of the line pattern was 2.43 × 10−6 Ω·m, which is ~10 times greater than that of the pattern formed using the CO2 laser. An X-ray diffraction analysis suggests that the balance between reduction and re-oxidation of the glyoxylic acid Cu complex determines the nature of the highly reduced Cu patterns in the ambient air.


2019 ◽  
Vol 9 (2) ◽  
pp. 358
Author(s):  
Wei Shi ◽  
Lei Yang ◽  
Lei Hou ◽  
Zenan Liu ◽  
Nuo Xu ◽  
...  

In this paper, the positive and negative symmetric pulses with a fast rising edge were generated by a GaAs photoconductive semiconductor switch (PCSS). When the GaAs PCSS was biased at 2.0 kV and triggered by a femtosecond laser pulse with a pulse energy of 97.5 J, the peak voltages of the positive and negative pulses were 1.313 kV and 1.329 kV, respectively, and the rise times were 174 ps and 164 ps, respectively. Moreover, the GaAs PCSS presents good stability. The experimental results show that GaAs PCSSs can meet the requirement of a femtosecond streak camera.


2017 ◽  
Vol 66 (6) ◽  
pp. 067902
Author(s):  
Tao Hai-Yan ◽  
Chen Rui ◽  
Song Xiao-Wei ◽  
Chen Ya-Nan ◽  
Lin Jing-Quan

2010 ◽  
Vol 97 (7) ◽  
pp. 071108 ◽  
Author(s):  
Xuan Yang ◽  
Jian Wu ◽  
Yuqi Tong ◽  
Liang’en Ding ◽  
Zhizhan Xu ◽  
...  

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