I am sick and tired of being a wage and hour slave. Is it ethical to just earn enough to get by, even if I am capable of doing more?

I am 39, a research engineer in the field of medical device. I have a degree in Biomedical engineering and a decade of experience, which is on the border of "experienced" and "older". <br><br>In the past decade I work as a contractor and now I have a long-term employment. In the past decade we went through two layoffs/restructurings, and I was able to beat my opponents and survived. <br>During these 10 years I have always experienced simmering anxiety on the security of my job and the pay, until I finally had a good contract for the next 3 years. <br><br>Now I am proud to announce that I am feeling very tired and demotivated. I feel that to be passionate about work is very exhausting, and I don't want to be passionate any more. I am so fed up to be valued based on how much money I can bring to my employers. <br><br>My current job has a contract that lasts three years, is highly paid (1.5 times median household income in my city, where the median is the average. Plenty of money). <br>It's a 9-4.5 job so 35 hours per week, no overtime, paid vacation. The job is about designing software for pacemakers. Not too exciting, but I am not passionate about it any more. <br><br>I am happy to do my job. But I want to do the bare minimum to meet the expectations and bug my bosses for raises. I want to experience the feeling of the joy of not caring about work. Become more lazy and more greedy is my next career development. I work as hard as I can just for money, I don't give a flying f about the product, the company. <br><br>I am so tired of being valued based on how much money I can bring to my employers. I am tired of the fact that my employers just view my life as a way of generating money. I am tired of the fact that my employers don't respect my desire of spending time with my family. I am tired of the fact that my employers don't want to pay me the market. I am tired of the fact that my employers want to exploit me and modify my contract in order to pay me less. I am tired of the fact that my employers think I am stupid and not able to see through their tactics of exploiting me. <br><br>Is it OK to do the bare minimum required and not do more? I do a job that is very important, I don't want to be responsible of my laziness, my greed of screwing up others. I want to do the minimum and not make mistakes. <br><br>Is it OK to bug my bosses to pay me more, despite doing the bare minimum and no more? Is it immoral not to use my full potential to be productive in my work? Is it immoral to ask for more money while doing the bare minimum? <br><br>I think so, that's why I am asking. I want to know what you guys think.