Particle-Based Inverted Crystal (IMAGE) University of Pittsburgh Caption The researchers created an ordered array of both 100 and 10 micro-meter particles. After chemically etching away the 100 micro-meter particles, what remains is a highly ordered porous material with both large and small pores whose sizes are completely tunable (via choice of initial particles). From left to right the panels show progressively wider frames. Credit Joseph McCarthy Usage Restrictions None License Licensed content 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.