We propose a simple self-repairing mechanism for small modules with dimensions in the order of a few centimeters. We aim to develop a number of simple modules with simple structure rather than the development of complicated modules, which operates in an accessible region. Reconfiguration is achieved without a sophisticated control for each module or telecommunications between modules. The morphological characteristics and probabilistic behavior of module, on the other hand, play an important role in the proposed self-repairing mechanism. We have developed this mechanism inspired by the self-repairing processes found in nature. A deformed structure consisting of a group of modules undergoes self-repair using the energy available in the external environment. We have investigated a self-repairing process by using small modules, which can be actuated by vibration. In the experiment, a vibrating parts feeder and the modules are placed on the surface of a vibrating plate. The time-asymmetric oscillations of the plate lead to translational and/or rotational motions of the modules on the plate surface. The cluster of modules are connected each other by a thin and loose wires in order to help the modules formed in a given shape. Each module is actuated by vibration from the plate in a particular manner, and the connection of the cluster is managed by the given structure in order to realize the self-repairing of its shape and function.

Whether the modules in these robots can be connected or not is determined stochastically without calculating the sequence of transformation. Therefore, the construction of modules used in stochastically self-configurable robots is simpler than that of deterministically self-reconfigurable robots. Reliability of deterministically self-reconfigurable robots is higher than that of stochastically robot. But, the modules used in these robots usually require a complicated structure and various components such as electronic circuits, sensors, actuators, batteries etc, thereby making it difficult to develop compact systems. In general, as their complexity increases, the reliability of robots decreases.

Based on the proposed mechanism, we have developed two different kinds of self-repairing structures:(i) simple components with no battery and (ii) a simple electric circuit with the function of illuminating LEDs. Regarding the LED illumination, the structure is consists of module mounted electrodes for power supply. Because the electrodes of modules are small, the modules we develop are required to be connected to the other modules at the correct position. In both cases, we use a permanent magnet as a connector for the modules. A permanent magnet does not consume any electric power for connection of modules. The magnetic force of a permanent magnet acts only in one direction and cannot be changed. Therefore, the module requires a mechanism to separate connected modules. The self-repairing structure we proposed requires no mechanism to remove connected modules, which are simply separated by applying large amount of vibration from the vibrating plate.