This past Thursday, Miguel Garcia-Garibay of UCLA spoke at Dartmouth College about his recent research regarding amphidynamic crystals. Amphidynamic crystals have recently become popular among researchers, largely due to strong ties to the world of molecular machines, which have proven useful in various chemical systems. Machines help reduce the amount of work needed for many tasks, including locomotion, the transformation of objects, and information storage. Garibay asserts that “the development of artificial molecular machines is one of the most important challenges of the 21st century, and presents a great opportunity to invest in science.”
Garibay’s initial inspiration to study molecular machines came from Leonardo da Vinci. Garibay drew parallels between the structure of naturally occurring crystals and the structure of several da Vinci-designed machines. He realized that, with the addition of programmable motion in the molecular system, crystals could be made to model both the behavior and the appearance of machines.
To understand why amphidynamic crystals are so special, it is first necessary to understand the relationship between order and the capacity for motion. Ordinarily, crystals exhibit a high degree of order, but very little motion. In contrast, liquids typically display a great deal of motion, but very little order. Plastic crystals lie in the middle of these two extremes, and experience rotational motion with a intermediate degree of structure. Amphidynamic crystals are substances that embody the best of both worlds, with motion equivalent to a typical liquid or gas phase and crystal-like order.
The study of amphidynamic crystals has become a relatively active field, largely due to the diversity of platforms that seem to work well for their synthesis. Modeling both gyroscopes and compasses, researchers established the physical characteristics of these crystals by creating molecular rotors, those that contained microscopic stators and rotators that could be affected by strong magnetic dipoles. Using solid-state chemistry and complex organic chemistry, Garibay’s team was able to successfully synthesize different molecular stators to design compounds that could be made in multigram scales. Subsequently, computational studies helped to build models that were used to understand the specific rotational characteristics of amphidynamic crystals in a more efficient and effective manner.
Improved understanding of the physical nature of amphidynamic crystals has allowed for numerous recent breakthroughs regarding the structure and organization of these substances. However, Garibay made it clear that the future of the field remains wide open, saying: “amphidynamic crystals can be designed and understood, but there is still a lot of work to be done.”