Swarmbots (IMAGE) Duke University Caption 'Swarmbots,' living cells engineered to produce monomer molecules, grow until they sense their population density has reached a certain level, whereupon they burst open, allowing the monomers to mingle and self-assemble into a composite polymer. Credit Zhuojun Dai 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.