Solin Tiermann was the son of Amanda and Ernest Tiermann. His father was a scientist from Earth and was famous for creating servo-furnishings. His only home was Tiermann's World. He was born on the flight bound there. His mother, Amanda, was a cyborg. When she died Solin was upset because he had been very close to her.
When he first met the Tenth Doctor and Martha, he asked Martha for a kiss, but she just laughed.
He was thrown into the dust corridor with his mother and nearly suffocated, but the Doctor cancelled out the Domovoi and saved Solin and Amanda. He opposed his father's loony idea of locking the Doctor down on Minus 30. He was the only Tiermann's to survive, and the Doctor took him to Spaceport Antelope Slash Nitelite with the last servo-furnishing, Barbara the drinks machine. (NSA: Sick Building)