With increasing presence of science throughout all parts of society, there are rising expectations for researchers to effectively communicate their work and for teachers to discuss contemporary findings in their classrooms. While the community can resort to established teaching aids for the fundamental concepts of most natural sciences, there is need for similarly illustrative demonstrators in neuroscience. We therefore introduce Lu.i: a parametrizable electronic implementation of the leaky integrate-and-fire neuron model in an engaging form factor. These palm-sized neurons can be used to visualize and experience the dynamics of individual cells and small networks. When stimulated with sensory input, Lu.i demonstrates brain-inspired information processing in the hands of a student. As such, it is actively used at workshops, in classrooms, and for science communication. As a versatile tool for teaching and outreach, Lu.i nurtures the comprehension of neuroscience research and neuromorphic engineering among future generations of scientists and the general public.