Hi, this is is a robot tea, it can make a perfect tea while you can doing something else, let's see how you can make one from cheap.
Green tea and black tea have different making time and temperature, 2 Minutes Green tea and 3 the black one, beyond the taste becomes bitter, and if you sways the tea bag, it improves the mixing.
First you need a bit higher chocolate box, a sg90 servo (about one dollar on aliexpress or ebay)
You also need a nipper (old earpones), two buttons, a switch, Atmega328p (Arduino on breadboard), male pins (for future program), the connections are very simple.
A 3,6V phone battery, two leds, an usb cable, hot glue, tin and welder to solder and pierce the plastic.
The battery can recharge directly trough the USB cable (red to +, balck to -), other pins are not used, the internal battery protection circuit will handle under and overcharge, you can fix all with hot glue, there are two leds, a green led for green tea and a red led for the balck tea.
Now you have to program the microcontroller with this code
Assuming a battery of 1Ah and an average consumption of 4 / 5h * 0,013A when stopped and 1 / 5h * 0.03A while moving, we will have an energy consumption of about 7mAh, then six days, or 3/60 7mAh * = 0,35mAh each black tea, then 1000 / 0.35 = 2857 blacks tea, with a charge of about 2 hours.
I hope you like it.
More info at http://electrogreen.altervista.org/robot-te/