Is it possible to store 1 mW power for required time and take 10 mW for some time?? whatever charging time i don't care but my output should be 10 times than input. I have only 1 source i.e. 1mW.
A battery does what you describe. For example, the discharge current can be 10X the charging current. However, it takes more than ten times longer to charge it than it takes to discharge it.
You'd need an inverter which would give you say 5v (USB charging). Assuming a 70% efficiency you'd get 0.7mw @ 5v which would be 5v@0.14ma - it would take a phone with a 1700ma/h battery 12142 hours (around a year and a half) to charge assuming a 100% efficient charging circuit in the phone.