Nanomaterials often undergo unusual mechanical deformations compared to their bulk counterparts when irradiated with ion-beams. This study visualizes and investigates some of the unusual interactions that can occur in nanomaterials during irradiation with medium-energy ion-beams using a Helium-Ion-Microscope (HIM). Ion-beam sculpting of semiconductor nanowires (NWs) with sub-10 nm features is demonstrated. Moreover, irradiation-induced growth of NWs at room-temperature is discovered. The new concept and possible mechanism of irradiation-induced VLS (vapor-liquid-solid) growth of NWs is introduced. These results are the basis for further fundamental and technological developments towards manipulation and visualization of ion-matter interactions at nanoscales.