Holly Evarts

latest from Holly Evarts

Image courtesy: Brett Sayles

Making computers more secure

Courtesy: Nathan R. Finney and Sanghoon Chae, Columbia Engineering

Vision and Discrete Sensors

Nonlinear optical process developed

An actor robot runs on a playpen trying to catch the visible green food, while an observer machine learns to predict the actor robot's behavior purely through visual observations. Although the observer can always see the green foods, the actor, from its own perspective, cannot due to occlusions. Courtesy: Creative Machines Lab/Columbia Engineering

Robot displays empathy to a partner robot

Laser beam transmitting upwards through glass. Courtesy: John Whitehead, Columbia University

Discrete Manufacturing

Laser inversion enables multi-materials 3D printing

Designed by big data and made with synthetic chemistry, this thin film and others like it could help reduce pollution and remove greenhouse gases from the air. Courtesy: Columbia University

AI and Machine Learning

Big Data, machine learning used to design gas separation membranes

PhD student Yan Xiong, Professor Sanat Kumar, Postdoc Jason Kahn, Professor Oleg Gang, and PhD student Brian Minevich, all members of the Soft Matter Lab at Columbia Engineering. The group made and partially characterized various optical and enzymatic materials to demonstrate a new nanofabrication platform. Courtesy: Columbia University

Discrete Manufacturing

Nanofabrication platform developed for directing components into 3D arrays

Illustration of controlled rotation of boron nitride (BN) layers above and below a graphene layer introduce coexisting moire superlattices, which change size, symmetry and complexity as a function of angle. In this system the Columbia researchers achieve unprecedented control over monolayer graphene's bandstructure within a single device, by mechanically rotating boron nitride atop graphene aligned to a bottom BN slab. Courtesy: Columbia University

Vision and Discrete Sensors

Restoring graphene’s symmetry with a twistable electronics device

A Hall-bar device structure (see inset) is wire-bonded to a 16-pin chip-carrier. The chip-carrier allows for extensive electrical characterization of the device at both low temperatures and high magnetic fields. Courtesy: Min Sup Choi/Columbia Engineering

Fabrication platform produces pristine 2-D transistors

Schematics of the protection mechanism of boron nitride (BN) and characterizations of BN nanofilm. The left visual shows that a Lithium aluminum titanium phosphate (LATP) pellet that touches lithium metal will be immediately reduced. The severe side reaction between lithium and solid electrolyte will fail the battery in several cycles. The right shows that an artificial BN film is chemically and mechanically robust against lithium. It electronically isolates LATP from lithium, but still provides stable ionic pathways when infiltrated by polyethylene oxide (PEO), and thus enables stable cycling. Courtesy: Yang Cheng, Columbia University

Technique produces longer-lasting lithium batteries