# Femtosecond Laser Processing of Biodegradable Polymers
## 2 Femtosecond Laser Processing of Biodegradable Polymers
\begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**Year** & **Wavelength** & **Pulse Width** & **Material** & **Note** & **Ref.** \\ \hline
2010 & 800 nm & 150 fs & PCL, PLA & evaluation of HAZ & [20] \\ \hline
2010 & 800 nm & 150 fs & PLLA-PCL copolymer & evaluation of cell alignment on direct laser written surface & [21] \\ \hline
2011 & 800 nm & 20 fs & PLA & 3D scaffold fabrication & [22] \\ \hline
2011 & 775 nm & 150 fs & PCL/gelatin & micro-patterned electrospun scaffold and cell behavior & [23] \\ \hline
2011 & 775 nm & 150 fs & PCL & effect of micro-channel on cell behavior & [24] \\ \hline
2011 & 1064 nm & 10 ps & PLLA & effect of crystallinity on micro-grating fabrication & [25] \\ \hline
2011 & 800 nm & 150 fs & PLA-PCL & effect of laser patterned surface on up regulation of myogenic markers & [26] \\ \hline
2012 & 800 nm & 100 fs & PLLA & effect of laser processed electrospun scaffolds on cell behavior & [27] \\ \hline
2012 & 800 nm & 120 fs & PLGA & micro-vessel scaffold fabrication & [28] \\ \hline
2012 & 248 nm, 248 nm & 20 ns, 150 ps, 500 fs & chitosan, starch, chitosan/starch & effect of pulse duration on porous surface fabrication & [29] \\ \hline
2013 & 800 nm & 150 fs & PLA-PCL & nano/micro-grating and cell behavior & [30] \\ \hline
2014 & 1064 nm & 10 ps & PLLA, PS & micro-patterned surface for cancer cell confinement & [31] \\ \hline
2014 & 800 nm & 30–100 fs & Gelatin, collagen, collagen, collagen-elastin & porous structure in ablation area, cell proliferation. & [32] \\ \hline
2014 & 1030, 515 nm & 400–800 fs & PLLA, Poly(D,-I-)actid & high repetition rate up to 500 kHz & [33] \\ \hline
2015 & 520 nm, 532 nm & 350 fs, 10 ps & PLLA, PLGA & parameter dependence & [34] \\ \hline
2015 & 800 nm, 400 nm & 100 fs & PLLA & LIPSS formation & [35] \\ \hline
2015 & 775 nm & 200 fs & PLGA, PPP & femtosecond laser ablation and MAPLE for cell adhesion & [36] \\ \hline
2015 & 1040 nm & 115 fs & PLA & processing in air and in water, high-rep rate of 57 MHz & [37] \\ \hline
2016 & 515 nm & 400 fs & PLLA electrospun fibers & fibrous platforms for cell adhesion and direction & [38] \\ \hline
2016 & 800 nm & 30 fs & Collagen/elastin & laser ablation for changing cell adhesion and wettability & [39] \\ \hline
2016 & 800 nm, 400 nm & 100 fs & PLGA & biodegradability depending on the laser wavelength & [40] \\ \hline
2016 & 515 nm & 450 fs & PLLA & experimental optimization of laser parameters & [41] \\ \hline
2017 & 800 nm, 400 nm & 100 fs & PLGA & release of loaded molecules after laser ablation & [42] \\ \hline
2017 & 266 nm & 100 fs, 5 ns & PLGA, PLLA & comparison of fs and ns lasers & [43] \\ \hline
2017 & 1030 nm & 180 fs, & PLA & nano-void formation & [44] \\ \hline
2018 & 800, 275 nm & 85 fs & PLA & comparison of six polymers & [45] \\ \hline
2018 & 800 nm & 30 fs & chitosan & texturing for bio-interfaces & [46] \\ \hline
2018 & 800 nm & 30 fs & PCL & osteoblast cell adhesion & [47] \\ \hline
2018 & 515 nm & 450 fs & PLLA & detailed study on physicochemical properties & [48] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._A considerable number of publications have been reported since the year 2000. One of the pioneering works was the fabrication of a biodegradable stent by using a femtosecond laser, which was reported by [PERSON] et al. They reported that the HAZ with femtosecond laser ablation was 1/10 the size of that using a CO\({}_{2}\) laser [9]. Although the details, including the material, were not described in the paper, the result showing the precise structure was sufficient to indicate the great potential of femtosecond lasers for polymer processing. [PERSON] et al. compared the results of an 800-nm femtosecond laser with those from a 193-nm nanosecond laser and reported that a smaller HAZ was observed in the case of the femtosecond laser, indicating the precise processing of the material [12]. As for a picosecond laser, [PERSON] et al.