High Noon Cyborg by Honey Phillips

Can a protective cyborg guard a brilliant scientist from a hidden threat?

Dr. Cassandra Winters has dedicated her life to the study of Mars and the mysteries beneath its surface. When strange readings emerge from a remote monitoring station, Cass sets off with her cybernetic armadillo Roland to investigate.
Cyborg ranger Z-542’s job is to protect, not to feel. He does his best to keep his distance from the humans on Mars—even the enticing little scientist he can’t stop thinking about. However when he discovers that Cass has headed out into the wilderness alone, nothing will stop him from going after her.
When an unexpected storm traps him with Cass, the attraction between them can no longer be ignored. But something dangerous is stirring beneath the surface of Mars. With danger closing in from above and below, can they protect each other—and admit the feelings blossoming between them?