Peter Schroeder, Shaler Arthur Hanisch Professor of Computer Science and Applied and Computational Mathematics, and colleagues have generated a computer simulation of underwater bubble rings that is so realistic it is virtually indistinguishable from a video of the real thing. "What drives me is finding these beautiful descriptions of something that looks terribly complicated but can be reduced to a few mathematical key concepts. Then the rest just follows from there. There's beauty in seeing that a very simple principle all of a sudden gives rise to the complex appearance we perceive," Professor Schröder says. [Caltech story]
MedE Professors Wei Gao and Lihong Wang are working on microrobots that can deliver drugs to specific spots inside the body while being monitored and controlled from outside the body. "These micromotors can penetrate the mucus of the digestive tract and stay there for a long time. This improves medicine delivery," Professor Gao says. "But because they're made of magnesium, they're biocompatible and biodegradable." [Caltech story]
Leonardo da Vinci studied the motion of blood in the human body. He was interested in the heart’s passive, three-cusp aortic valve, which he realized must be operated by the motion of blood. He theorized that vortices curl back to fill the cusps in the flask-shaped constriction at the aorta’s neck. Morteza Gharib, Hans W. Liepmann Professor of Aeronautics and Bioinspired Engineering; Booth-Kresa Leadership Chair, Center for Autonomous Systems and Technologies; Director, Graduate Aerospace Laboratories; Director, Center for Autonomous Systems and Technologies, has used modern imaging techniques to demonstrate the existence of the revolving vortices that Leonardo interpreted as closing the valve. [Nature Article]
A team of researchers including Noah Olsman (PhD ’19), John Doyle, Jean-Lou Chameau Professor of Control and Dynamical Systems, Electrical Engineering, and Bioengineering, and Richard Murray, Thomas E. and Doris Everhart Professor of Control and Dynamical Systems and Bioengineering, has developed a set of guidelines for designing biological circuits using tools from mechanical and electrical engineering. Like electric circuits—but made out of cells and living matter—biological circuits show promise in producing pharmaceuticals and biofuels. [Caltech story]
Katie Bouman, Assistant Professor of Computing and Mathematical Sciences, creates images from nonideal sensor data and mines for information from images using techniques that can be applied to everything from medical imaging to studying the universe. She likes to search for information hidden in images, imperceptible to humans, that she can use to learn about the environment around us. [Profile of new EAS faculty member Professor Bouman]
Chiara Daraio, Professor of Mechanical Engineering and Applied Physics, was invited to give the Spring 2019 Elsevier Distinguished Lecture in Mechanics at Princeton. Her lecture was entitled “Mechanics of Robotic Matters.” She discussed recent progress in the design of micro- and macro-scale, nonuniform materials that can bend into freeform objects, in response to environmental stimuli or with simple application of point loads. She also showed how the use of responsive materials, like shape memory polymers and liquid crystal elastomers, allows creating new, passive soft robots. [Elsevier Lecture]
Professors Chung, Anandkumar, and Yue have teamed up to develop a system that uses a deep neural network to help autonomous drones "learn" how to land more safely and quickly, while gobbling up less power. The system they have created, dubbed the "Neural Lander," is a learning-based controller that tracks the position and speed of the drone, and modifies its landing trajectory and rotor speed accordingly to achieve the smoothest possible landing. The new system could prove crucial to projects currently under development at CAST, including an autonomous medical transport that could land in difficult-to-reach locations (such as a gridlocked traffic). "The importance of being able to land swiftly and smoothly when transporting an injured individual cannot be overstated," says Professor Gharib who is the director of CAST; and one of the lead researchers of the air ambulance project. [Caltech story]
Professor Lihong Wang and Postdoctoral Scholar Dr. Junhui Shi have developed a new imaging technique that uses pulses from two kinds of lasers to take pictures of microscopic biological structures. This new approach, called ultraviolet-localized mid-infrared photoacoustic microscopy, or ULM-PAM, develops images of the microscopic structures found in a piece of tissue by bombarding the sample with both infrared and ultraviolet laser light. "Because ultraviolet light and infrared have different properties, we had to find special mirrors and glass that could focus both," Dr. Shi says. "And because no camera exists that can see both, we had to develop ways to see if they were correctly focused." [Caltech story]
Congratulations to the entire Event Horizon Telescope team, and especially to Dr. Katie Bouman who is joining the Engineering and Applied Science (EAS) Division in June as assistant professor of computing and mathematical sciences (CMS). Currently, Caltech and CO Architects are working with her to design and construct a unique laboratory that will facilitate her work in computational imaging. The laboratory is the first of its kind and is designed for her to conduct experimental work in conjunction with her computational approaches – making it possible, for instance, to observe phenomena previously difficult or impossible to measure. The black hole imaging is one spectacular example of how Professor Bouman’s algorithms are advancing our knowledge of the world; she has also developed algorithms that let us “see around corners” and detect material properties (such as stiffness and dampness) via imaging. In her work, Bouman has also developed methods to combine information from both imaging as well as acoustic systems to analyze sub-pixel scale vibrations of otherwise seemingly still objects. As a result, relatively inexpensive cameras, combined with powerful algorithms, are an increasingly attractive alternative to complex and expensive laser-based systems to sense “invisible” attributes of a material. [Caltech story - How to Take a Picture of a Black Hole]
Lihong Wang, Bren Professor of Medical Engineering and Electrical Engineering, and colleagues are using photoacoustic microscopy (PAM) to improve on an existing technology for measuring the oxygen-consumption rate (OCR). This new method allows the researchers to determine how oxygenated a sample of blood is by "listening" to the sound it makes when illuminated by the laser. Professor Wang calls this single-cell metabolic photoacoustic microscopy, or SCM-PAM. [Caltech story]
