Virtual Walls (video) University of Missouri-Columbia Share Print E-Mail Loading video... Caption An oil droplet is pushed by air and squeezed tightly between two repellent surfaces, which form virtual walls on both sides of the oil droplet. The oil droplet can move only along the path defined by the virtual walls. Credit Dr. Jae Kwon Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.