Chapter 27
Crawling and Bending Motions
of Azobenzene Derivatives Based
on Photoresponsive Solid–Liquid Phase
Transition System
Yasuo Norikane, Koichiro Saito, and Youfeng Yue
Abstract In this chapter, the concept of the photoinduced solid–liquid phase transition and its wide area of possible application are introduced. Also, two macroscopic motions induced by the synergetic action of isomerization of azobenzene
molecules are described: firstly, the crawling motion of crystals of azobenzene
derivatives on a glass surface by light irradiation with two or one light sources.
The motion of the crystals is continuous, and it can be generated by simple experimental setups. Secondly, the reversible bending motion of liquid crystalline polymer
network consisting azobenzene monomer as a crosslinker. This polymer also changes
its glass transition temperature reversibly upon light irradiations.
Keywords Azobenzene · Crystal · Liquid · Glass · Photoisomerization ·
Crawling · Bending
27.1 Introduction
Nature has developed fascinating molecular systems and organisms that convert light
energy into chemical energy and kinetic energy. They also use light as information
for communication or signal that triggers for living activities. Scientists have been
inspired those natural systems as research subjects to learn the mechanism and even
to mimic to fabricate typical functions of living systems. In particular, the motion
of objects driven by light stimuli has attracted significant attention, because light
is a powerful energy source and an excellent tool for triggering and controlling the
direction of the motion. Various artificial systems have been established to move
objects in molecular size to centimeter size. For example, optical manipulation or
optical trapping and transporting are successful tools in optics, physics, biology, and
chemistry [1]. Laser beam produces optical forces, and it is used as optical tweezers
and optical torque to manipulate in microscale to nanoscale. The advantage in this
Y. Norikane (B) · K. Saito · Y. Yue
Research Institute for Advanced Electronics and Photonics, National Institute of Advanced
Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
e-mail: y-norikane@aist.go.jp
© Springer Nature Singapore Pte Ltd. 2020
H. Miyasaka et al. (eds.), Photosynergetic Responses in Molecules
and Molecular Aggregates, https://doi.org/10.1007/978-981-15-5451-3_27
465
Crawling and Bending Motions
of Azobenzene Derivatives Based
on Photoresponsive Solid–Liquid Phase
Transition System
Yasuo Norikane, Koichiro Saito, and Youfeng Yue
Abstract In this chapter, the concept of the photoinduced solid–liquid phase transition and its wide area of possible application are introduced. Also, two macroscopic motions induced by the synergetic action of isomerization of azobenzene
molecules are described: firstly, the crawling motion of crystals of azobenzene
derivatives on a glass surface by light irradiation with two or one light sources.
The motion of the crystals is continuous, and it can be generated by simple experimental setups. Secondly, the reversible bending motion of liquid crystalline polymer
network consisting azobenzene monomer as a crosslinker. This polymer also changes
its glass transition temperature reversibly upon light irradiations.
Keywords Azobenzene · Crystal · Liquid · Glass · Photoisomerization ·
Crawling · Bending
27.1 Introduction
Nature has developed fascinating molecular systems and organisms that convert light
energy into chemical energy and kinetic energy. They also use light as information
for communication or signal that triggers for living activities. Scientists have been
inspired those natural systems as research subjects to learn the mechanism and even
to mimic to fabricate typical functions of living systems. In particular, the motion
of objects driven by light stimuli has attracted significant attention, because light
is a powerful energy source and an excellent tool for triggering and controlling the
direction of the motion. Various artificial systems have been established to move
objects in molecular size to centimeter size. For example, optical manipulation or
optical trapping and transporting are successful tools in optics, physics, biology, and
chemistry [1]. Laser beam produces optical forces, and it is used as optical tweezers
and optical torque to manipulate in microscale to nanoscale. The advantage in this
Y. Norikane (B) · K. Saito · Y. Yue
Research Institute for Advanced Electronics and Photonics, National Institute of Advanced
Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
e-mail: y-norikane@aist.go.jp
© Springer Nature Singapore Pte Ltd. 2020
H. Miyasaka et al. (eds.), Photosynergetic Responses in Molecules
and Molecular Aggregates, https://doi.org/10.1007/978-981-15-5451-3_27
465