Electrically self-powered active disassembly

Active disassembly using smart materials is a concept developed at Brunel University for the design of assemblies with the built-in capability for easy separation of components for recycling on exposure to certain triggering conditions. Such assemblies incorporate shape memory alloy (SMA) actuators in the product housings. These actuators in the form of clips can undergo a shape change (shape memory effect) on going above a transition temperature, and exert a force to effect disassembly. Hitherto, such a change in temperature has been effected by direct heat input external to the assembly. It is now shown in the case of assemblies that contain battery power sources, firstly, that disassembly can be achieved using the residual electrical energy in waste batteries to heat the SMA actuator electrically and, secondly, that there is enough energy left in end -of-life batteries of mobile phones and end-of-life vehicles to trigger at least 4 and 16 devices respectively.