How to Make a Smart Capsule (IMAGE) Washington University in St. Louis Caption Attach a smart polymer to your gold nanocage, seen here in cross section with the pores at the corners. To load the cages, shake them in a solution of the drug at a temperature above the polymer's critical temperature. Let the cages cool, so that the polymer chains stand up like brushes, sealing the cage's pores. To release the drug, expose the cages to laser light (the lightning bolt) at their resonant frequency, heating them just enough to drive the polymer over its critical temperature. The polymer chains will collapse, opening the pores, and releasing the drug. The cage can be resealed simply by turning off the light. Credit Younan Xia, Washington University in St. Louis 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.