Bubble Array (IMAGE) Penn State Caption This is a chip-scale glass microspherical shell sensor array blown on a silicon substrate. Insert is a near-perfect spherical shell. Credit Tadigadapa Lab/Penn State Usage Restrictions Non commercial use only 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.