You,said fully sentient that implies as a companion, being able to think,freely .
Computers will always just be machines. Only God can create a soul. Robots are useful for certain tasks. They can be programmed, and learn by themselves to a certain extent. I do think that robots could be useful to the elderly and other shut ins. To help them do daily tasks, and to talk to them. They will never have a soul though.
Not Alexa with arms and legs a robot as she can't actually posses a personality .
A robot may indeed develop a personality. My car learns my driving style, and optimizes engine performance accordingly. Robots can be programmed with general knowledge, and tailor their talk to the personality of their owners. Learn what interests their owners, and talk about those topics.
A companion, can't simply be logarithmic function that has studied you for months and called a friend when its just a version of you talking to you but in person instead of in your head.
Possibly. Consider that many people find companionship with pets, even though their pets will never interact with them on a peer level. Its possible that some shut ins will similarly find helpful robots provide them some companionship. Time will tell, if robot technology continues to advance.
That's self aware
Okay, you define it differently than I do. I was just thinking of a learning machine that people can interact with to help them get daily tasks done. Alexa, please make a pot of coffee for me. Alexa, I want to learn about a topic via debate, please take the other side of my argument. Schools such as Harvard use such debate tactics as part of their learning process. Robots could do similar. Alexa, please teach me Spanish, or lets talk about the news.