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D. George and M. J. Madou
of the two-dimensional shapes was performed manually, this welding method has
the potential to be extended to smaller dimensions. In a fabrication system, which
is a fusion of both direct writing and wet origami technique, origami shapes are
obtained by the folding of a directly written layer [2]. The folding is facilitated by
the solvent contained in ink, which controls the storage modulus of the structure. The
storage modulus increases as the solvent evaporate from the structure. Therefore, a
graded volatility solvent system is adopted to have better control over the mechanical
properties of the sheets and, thus, a controlled folding [2]. This technique has the
capability or makes TiH 2 shape, which later can be converted into TiO 2 by annealing
at 1050 °C for 2 h in air. Here patterning is performed by cutting the film, and folding
is carried out manually. Another method for making permanently folded shapes is
by designing parylene C balloons filled with paraffin wax at the hinges [150]. Wax is
melted by sending Joule current to a heater that is fabricated on balloons. The hinges
become flexible as a result of this process. The bending is achieved manually, and the
heater is turned off to obtain the required rigidity of the folds. The folded shape will
go back to the original shape upon reheating. The major drawback of this method is
the involvement of complicated fabrication routes and the difficulty associated with
injecting wax into the balloons.
5 Carbon Origami MEMS
Carbon microparticles and micropatterns have found various applications, including
sensors, flexible electronics, and photonics owing to their unique properties. Surface
area, topology, and material properties of carbon influence the design and development of those types of system components. All these qualities can be controlled
with the origami design techniques. Releasing of the two-dimensional elements
from supporting structures itself increases the available surface area. Folding them
and tightly packing them could further increase the available surface area in a unit
volume and can create complex topologies that are otherwise difficult to achieve.
Carbon also possesses excellent mechanical properties. Shapes like Miura-ori can
favorably modify overall mechanical properties even further [101, 134]. However,
the carbon materials that we see in day-to-day life are not foldable. That begs the
question: how can we make folded carbon shapes?
There are three significant ways to fabricate carbon-based origami.
(1) By folding graphene or graphene-based materials
Although most of the carbon materials that we are accustomed to are brittle, carbon
sheets made of single or multiple layers or atoms—single layer or multilayer
graphene—are flexible. Researchers observed sudden changes in the profiles during
atomic force microscopy (AFM) scanning of functionalized graphene sheets (FGS).
Such changes in the horizontal scan lines indicate the folded FGS resulting from the
lateral force exerted by the AFM tip. It proves that the folding of FGS is possible with
D. George and M. J. Madou
of the two-dimensional shapes was performed manually, this welding method has
the potential to be extended to smaller dimensions. In a fabrication system, which
is a fusion of both direct writing and wet origami technique, origami shapes are
obtained by the folding of a directly written layer [2]. The folding is facilitated by
the solvent contained in ink, which controls the storage modulus of the structure. The
storage modulus increases as the solvent evaporate from the structure. Therefore, a
graded volatility solvent system is adopted to have better control over the mechanical
properties of the sheets and, thus, a controlled folding [2]. This technique has the
capability or makes TiH 2 shape, which later can be converted into TiO 2 by annealing
at 1050 °C for 2 h in air. Here patterning is performed by cutting the film, and folding
is carried out manually. Another method for making permanently folded shapes is
by designing parylene C balloons filled with paraffin wax at the hinges [150]. Wax is
melted by sending Joule current to a heater that is fabricated on balloons. The hinges
become flexible as a result of this process. The bending is achieved manually, and the
heater is turned off to obtain the required rigidity of the folds. The folded shape will
go back to the original shape upon reheating. The major drawback of this method is
the involvement of complicated fabrication routes and the difficulty associated with
injecting wax into the balloons.
5 Carbon Origami MEMS
Carbon microparticles and micropatterns have found various applications, including
sensors, flexible electronics, and photonics owing to their unique properties. Surface
area, topology, and material properties of carbon influence the design and development of those types of system components. All these qualities can be controlled
with the origami design techniques. Releasing of the two-dimensional elements
from supporting structures itself increases the available surface area. Folding them
and tightly packing them could further increase the available surface area in a unit
volume and can create complex topologies that are otherwise difficult to achieve.
Carbon also possesses excellent mechanical properties. Shapes like Miura-ori can
favorably modify overall mechanical properties even further [101, 134]. However,
the carbon materials that we see in day-to-day life are not foldable. That begs the
question: how can we make folded carbon shapes?
There are three significant ways to fabricate carbon-based origami.
(1) By folding graphene or graphene-based materials
Although most of the carbon materials that we are accustomed to are brittle, carbon
sheets made of single or multiple layers or atoms—single layer or multilayer
graphene—are flexible. Researchers observed sudden changes in the profiles during
atomic force microscopy (AFM) scanning of functionalized graphene sheets (FGS).
Such changes in the horizontal scan lines indicate the folded FGS resulting from the
lateral force exerted by the AFM tip. It proves that the folding of FGS is possible with