1 Introduction to Laser Micro-to-Nano Manufacturing
25
Fig. 1.20 Applications of photothermal effects, a photonic sintering (Reprinted with permission
from [94]. Copyright 2012. Springer Nature.), b laser direct writing (Reprinted with permission
from [98]. Copyright 2015 Royal Society of Chemistry)
than that generated in silver. Also, similar to Ag nanowires, heat generation is highly
localized and self-contained in the junction point, creating “hot spots”. Despite the
heat at the hot spots can rapidly spread to the whole Ag nanoplate because of the
high thermal conductivity of silver, the heat could be contained in several to hundreds
nanometers scale depended on the size and shape of the nanostructures [61].
Besides the aforementioned merits, such as, highly localized heating and efficient light conversion, light-induced heat generation can be well controlled by
multiple factors: material absorption involving material, geometrical morphology,
size, etc., and incident light properties, such as light intensity, dose, polarization,
direction, spectra and even pulse parameters for pulsed light sources. For example,
the photothermal effects shows strong wavelength dependency in the silver/PVP
nanocluster. The peaks in the heat-wavelength curves (Fig. 1.19b) typically reveals
the strong surface plasmon resonance as well as the high efficient heat generation.
Therefore, photothermal effects in nanocomposites naturally stimulate vast physical
processes and chemical reactions with unprecedented spatial and temporal controls
[94, 96]. Shown in Fig. 1.20, applications of photothermal effects have been extend
to the fields as photothermal therapy [97, 100], laser direct writing [98], photonic
sintering [94], solar energy harvesting [62], surface modification [99], and so on.
1.4 Photothermal Versus Photonic Nonthermal
Manufacturing
1.4.1 Photonic Sintering
Photonic sintering is critical for printed electronics and 3D printing. Compared to
conventional thermal sintering photonic sintering is a local effect by highly selected
25
Fig. 1.20 Applications of photothermal effects, a photonic sintering (Reprinted with permission
from [94]. Copyright 2012. Springer Nature.), b laser direct writing (Reprinted with permission
from [98]. Copyright 2015 Royal Society of Chemistry)
than that generated in silver. Also, similar to Ag nanowires, heat generation is highly
localized and self-contained in the junction point, creating “hot spots”. Despite the
heat at the hot spots can rapidly spread to the whole Ag nanoplate because of the
high thermal conductivity of silver, the heat could be contained in several to hundreds
nanometers scale depended on the size and shape of the nanostructures [61].
Besides the aforementioned merits, such as, highly localized heating and efficient light conversion, light-induced heat generation can be well controlled by
multiple factors: material absorption involving material, geometrical morphology,
size, etc., and incident light properties, such as light intensity, dose, polarization,
direction, spectra and even pulse parameters for pulsed light sources. For example,
the photothermal effects shows strong wavelength dependency in the silver/PVP
nanocluster. The peaks in the heat-wavelength curves (Fig. 1.19b) typically reveals
the strong surface plasmon resonance as well as the high efficient heat generation.
Therefore, photothermal effects in nanocomposites naturally stimulate vast physical
processes and chemical reactions with unprecedented spatial and temporal controls
[94, 96]. Shown in Fig. 1.20, applications of photothermal effects have been extend
to the fields as photothermal therapy [97, 100], laser direct writing [98], photonic
sintering [94], solar energy harvesting [62], surface modification [99], and so on.
1.4 Photothermal Versus Photonic Nonthermal
Manufacturing
1.4.1 Photonic Sintering
Photonic sintering is critical for printed electronics and 3D printing. Compared to
conventional thermal sintering photonic sintering is a local effect by highly selected