Physico-chemists develop active photochromic colloids that demonstrate the development (New Active Smart Materials developed) of new active smart materials.
In nature, the skin of cephalopods (animals with tentacles attached to the head) has an incredible ability to adapt. Their skin contains a certain type of pigment that can detect changes in ambient light conditions and adjust their appearance through the action of pigment cells.
Although it is complex in nature, the ability to change color depends primarily on the mechanism of action in which the particles are bent or expanded under the control of the radial nerve.
Inspired by this natural process, a research team of Dr. Jinyao TANG from the Department of Chemistry at The University of Hong Kong (HKU), is developing an intelligent colloidal system that chooses to cooperate to achieve the separation of multidimensional systems controlled by light.
With Scientists from the Hong Kong University of Science and Technology and Xiamen University. The group creates powerful photochromic nanoclusters by mixing cyan, magenta and yellow microbeads, achieving high photochromism.
This macroscopic photochromism is based on the vertical stratification of the light-induced mixture of active microbeads, resulting in the proliferation of microbeads with colors corresponding to the incident spectrum.
Unlike the current color changing materials, this new colloidal photochromic swarm relies on the reorganization of existing pigments rather than the generation of new chromophores in situ and is more reliable in the program.
Their research provides a simple method for applications such as electronic ink, screens and optical cameras, representing a major advance in the field of active materials. The research results were recently published in the prestigious academic journal Nature.
Self-activating substances are micro/nanoparticles that mimic the swimming of microorganisms in water. Recently, they have attracted much attention in the fields of nanoscience and non-scale physics and are being developed for potential biomedical applications.
One of the main research goals of functional molecules is to develop medical micro/nanrobots based on these materials for non-invasive drug delivery and surgery. However, the nature of the work is very simple, and they drive the system and the understanding of the environment is great.
In particular, the size and simple structure of the micro/nano particles prevent the complexity of implementing their functions in the body. The challenge and the main thing that determines the application of the future is how to create things that work with smart features despite their simple structure.
Light-emitting microswimmers, a type of autonomous device, have recently been developed with the aim of creating a controlled nanorobot, which provides the potential for biomedical applications and new mechanical devices. as swimming activity, structural composition and interparticle interactions can change rapidly. and incident light.
On the other hand, light not only stimulates photosensitive movement in microswimmers, but changes the effectiveness of the interaction between the body.
For example, photocatalytic reactions can change the local chemical gradient field, which in turn affects the movement conditions of nearby objects through the effect of diffusion swimming, resulting in long-term attraction or cold water In this work, Tang’s team designed a simple TiO2 functionalized microbead system of long wavelengths based on their previous research on light-activated microswimmers.
During photoexcitation, the redox reaction in the TiO2 creates a chemical gradient, which effectively controls the interaction of the beneficial particles. That is, the particle-value interaction can be controlled by combining incident light of different wavelengths and intensities.
TiO2 microbeads with different photo-sensitivity programs can be created by selecting color coding with different characteristics. By mixing several types of TiO2 microbeads that are similar to dyeing the fabric of different absorption types and adjusting the type of incident light, the desired isolation is achieved.
The purpose of obtaining particle fraction segregation is to control the concentration and dispersion of the body in the liquid at the micro and macro level. In fact, this produced a new photo ink by mixing microbeads with different photo effects that can be applied to e-books.
The pattern is similar to a cluster of pigments in the skin of cephalopods that can see the light conditions of the environment and change the appearance of the surrounding pigment cells through their corresponding behavior.
“The research results have greatly contributed to improving our knowledge of artificial intelligence in artificial objects and opened the door to the creation of new smart objects. With this progress, we are responsible for the development of photo chromic ink is being programmed that can be used in a variety of applications such as electronic ink, display ink, and even active optical ink,” said Dr. Jinyao concluded.
Source: The University of Hong Kong
