Nanorobot propelling sperm. Computer illustration of a nanorobot propelling a spermatozoon (sperm) towards the egg (lower left) for fertilisation. Tiny robots like this may be used in infertility treatment, allowing fertilisation to occur in the body where otherwise in vitro fertilisation (IVF) would be necessary. Nanorobots could also be used to detect and repair defects in the body's organs and tissues, travelling to their destination through tubes such as the blood vessels. Damaged or blocked blood vessels themselves could be repaired from within to restore healthy blood flow.