Single-step fabrication of microfluidic channels filled with nanofibrous membrane using femtosecond laser irradiation

In this paper, we demonstrate a new method of fabricating silicon microfluidic channels filled with a porous nanofibrous structure utilizing a femtosecond laser. The nanofibrous structure can act as a membrane used for microfiltration. This method allows us to generate both the microfluidic channel and the fibrous nanostructure in a single step under ambient conditions. Due to laser irradiation, a large number of nanoparticles ablate from the channel surface, and then aggregate and grow into porous nanofibrous structures and fill the channels. Energy dispersive x-ray spectroscopy (EDS) analysis was conducted to examine the oxygen concentration in the membrane structure. Our results demonstrated that by controlling the laser parameters including pulse repetition, pulse width and scanning speed, different microfluidic channels with a variety of porosity could be obtained.

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Single-step fabrication of microfluidic channels filled with nanofibrous membrane using femtosecond laser irradiation

10.32920/14636256 ◽

2021 ◽

Author(s):

Amirhossein Tavangar ◽

Bo Tan ◽

Krishnan Venkatakrishnan

Keyword(s):

Femtosecond Laser ◽

Laser Irradiation ◽

Microfluidic Channel ◽

Scanning Speed ◽

Single Step ◽

Femtosecond Laser Irradiation ◽

Microfluidic Channels ◽

Ambient Conditions ◽

Nanofibrous Structure ◽

Channel Surface

In this paper, we demonstrate a new method of fabricating silicon microfluidic channels filled with a porous nanofibrous structure utilizing a femtosecond laser. The nanofibrous structure can act as a membrane used for microfiltration. This method allows us to generate both the microfluidic channel and the fibrous nanostructure in a single step under ambient conditions. Due to laser irradiation, a large number of nanoparticles ablate from the channel surface, and then aggregate and grow into porous nanofibrous structures and fill the channels. Energy dispersive x-ray spectroscopy (EDS) analysis was conducted to examine the oxygen concentration in the membrane structure. Our results demonstrated that by controlling the laser parameters including pulse repetition, pulse width and scanning speed, different microfluidic channels with a variety of porosity could be obtained.

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A new approach to fabricate PDMS structures using femtosecond laser

10.32920/ryerson.14644545 ◽

2021 ◽

Author(s):

Hamsapriya Selvaraj

Keyword(s):

Femtosecond Laser ◽

Laser Irradiation ◽

Hybrid Structure ◽

Single Step ◽

Femtosecond Laser Irradiation ◽

Nanoindentation Test ◽

Nanoscale Structures ◽

Al Nanoparticles ◽

2D And 3D ◽

Intensity Regime

Polydimethylsiloxane (PDMS) is commonly used to prototype micro and nano featured components due to its beneficial properties. PDMS based devices have been used for diverse applications such as cell culturing, cell sorting and sensors. Motivated by such diverse applications possible through pure PDMS and reinforced PDMS, numerous efforts have been directed towards developing novel fabrication techniques. Prototyping 2D and 3D pure and reinforced PDMS microdevices normally require a long curing time and must go through multiple steps. This research explores the possibility of fabricating microscale and nanoscale structures directly from PDMS resin using femtosecond laser processing. This study offers an alternative fabrication route that potentially lead to a new way for prototyping of pure and reinforced PDMS devices, and the generation of hybrid nanomaterials. In depth investigation of femtosecond laser irradiation of PDMS resin reveals that the process is highly intensity-dependent. At low to intermediate intensity regime, femtosecond laser beam is able to rapidly cure the resin and create micron-sized structures directly from PDMS resin. At higher intensity regime, a total break-down of the resin material occurs and leads to the formation of PDMS nanoparticles. This work demonstrates a new way of rapid curing of PDMS resin on a microsecond timescale using femtosecond laser irradiation. The proposed technique permits maskless single-step curing and is capable of fabricating 2D and 3D structures in micro-scale. Reinforced PDMS microstructures also have been fabricated through this method. The proposed technique permits both reinforcement and rapid curing and is ideal for fabricating reinforced structures in microscale. The strength of the nanofiber reinforced PDMS microstructures has been investigated by means of Nanoindentation test. The results showed significant improvement in strength of the material. Hybrid PDMS-Si and hybrid PDMS-Al nanoparticle aggregate were generated using femtosecond laser. The results indicate that the hybrid PDMS nanostructures are clusters of nanoparticles that agglomerate and interweave three-dimensionally and also the possibility of formation of Si/Al nanoparticles enclosed in PDMS Shells. Presence of PDMS in the final hybrid structure is confirmed by micro-raman analysis. The versatility of our technique opens a new pathway to generate hybrid 3D fibrous nanostructures on any materials.

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A new approach to fabricate PDMS structures using femtosecond laser

10.32920/ryerson.14644545.v1 ◽

2021 ◽

Author(s):

Hamsapriya Selvaraj

Keyword(s):

Femtosecond Laser ◽

Laser Irradiation ◽

Hybrid Structure ◽

Single Step ◽

Femtosecond Laser Irradiation ◽

Nanoindentation Test ◽

Nanoscale Structures ◽

Al Nanoparticles ◽

2D And 3D ◽

Intensity Regime

Polydimethylsiloxane (PDMS) is commonly used to prototype micro and nano featured components due to its beneficial properties. PDMS based devices have been used for diverse applications such as cell culturing, cell sorting and sensors. Motivated by such diverse applications possible through pure PDMS and reinforced PDMS, numerous efforts have been directed towards developing novel fabrication techniques. Prototyping 2D and 3D pure and reinforced PDMS microdevices normally require a long curing time and must go through multiple steps. This research explores the possibility of fabricating microscale and nanoscale structures directly from PDMS resin using femtosecond laser processing. This study offers an alternative fabrication route that potentially lead to a new way for prototyping of pure and reinforced PDMS devices, and the generation of hybrid nanomaterials. In depth investigation of femtosecond laser irradiation of PDMS resin reveals that the process is highly intensity-dependent. At low to intermediate intensity regime, femtosecond laser beam is able to rapidly cure the resin and create micron-sized structures directly from PDMS resin. At higher intensity regime, a total break-down of the resin material occurs and leads to the formation of PDMS nanoparticles. This work demonstrates a new way of rapid curing of PDMS resin on a microsecond timescale using femtosecond laser irradiation. The proposed technique permits maskless single-step curing and is capable of fabricating 2D and 3D structures in micro-scale. Reinforced PDMS microstructures also have been fabricated through this method. The proposed technique permits both reinforcement and rapid curing and is ideal for fabricating reinforced structures in microscale. The strength of the nanofiber reinforced PDMS microstructures has been investigated by means of Nanoindentation test. The results showed significant improvement in strength of the material. Hybrid PDMS-Si and hybrid PDMS-Al nanoparticle aggregate were generated using femtosecond laser. The results indicate that the hybrid PDMS nanostructures are clusters of nanoparticles that agglomerate and interweave three-dimensionally and also the possibility of formation of Si/Al nanoparticles enclosed in PDMS Shells. Presence of PDMS in the final hybrid structure is confirmed by micro-raman analysis. The versatility of our technique opens a new pathway to generate hybrid 3D fibrous nanostructures on any materials.

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