“SMORES-EP is a modular robot designed and built at the University of Pennsylvania, and used by researchers at Penn and Cornell. SMORES stands for Self-Assembling MOdular Robot for Extreme Shapeshifting, and EP refers to the Electro-Permanent magnets the modules use to connect.
SMORES-EP modules have four degrees of freedom (pan, tilt, and left/right wheels). The left and right wheels have rubber tired, and allows the module to drive like a car on flat surfaces. Each module has its own battery, and communicates with a central computer over 802.11 WiFi. So far, 24 modules have been built.
Each of the four faces of the module is equipped with an array of electro-permanent (EP) magnets that can form a strong connection with other modules, or with metal objects. Each EP magnet consist of an electromagnet coil wrapped around a pair of permanent magnet cores, and can be turned on and off by sending a pulse of current through the coil. With the magnets turned on, a connected modules sustain a holding force of 89 Newtons with no power consumption – they only require power when connecting and disconnecting. SMORES-EP modules communicate with one another by exploiting the inductive coupling of the magnets, essentially using them as short-range radios.”