How similar?
He did not use motors at all
Also see post #4
This little board (shown below) will drive 2 motors forward and backwards, so you will need 50 of them. However you will need to reduce the voltage to 11V or less. Each motor driver will need two control signals, so for 100 motors you will need 200 control signals. As I previously mentioned, you can use port expanders to gain additional pins.
Buy one and try a test setup with a port expander.
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You need to choose one.
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Hi, @is1234
Welcome to the forum.
Do you have a DMM? Digital MultiMeter?
Measure the current.
Tom.... 
Before you order 100 motors and 100 drivers plus expanders, ask if you are able to write the code for that. And will Mega be able to take care of that code?
It looks like the MIT device used miniature linear actuators, possibly similar to these. Those are much more complicated than motors, as they have to move different distances, stop, reverse to another distance, etc.
In any case, get one "motor" working perfectly, before ordering 99 more.
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I would get a few motors as indicated by your experience you will probably fry them. Also same for the Arduino and driver boards. If I am wrong, great and you will have some parts to continue onward.
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Thank you for the recommendation. I have done so and am attaching a picture of the measured resistance. However, I have a point of confusion. Since the voltage is 12V, is the current I=V/R=(12)/(11.5)=1.04A? I measured amps and obtained 0.05A.
I am a high school sophomore. I have much more experience on the mechanical side of things, however, I have much less experience in electrical or programming.
Hello, I expected some kind of linear actuator on a motor, as I saw no other way of having each block move up to different heights. However, because of budget issues, I am using a 3d printed geared down gearbox with a linear rack.
The 1.04A is the start/stall current, which the motor briefly draws every time it starts up, or while it is stalled.
The 0.05A is the no load, free running current and will increase rapidly as the motor shaft is loaded. Pinch the shaft with your fingers to see the effect.
Those are typical values for a rather small toy motor.
The MIT project stops the columns at varied heights in between the limits of motion:
Do you plan on controlling variable height somehow? With sensors?
See post #22
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For a totally erroneous answer.
Because we are not using stepping motors here.
After some research, I found this MCP23017 chip. It is much less expensive than the chip you recommended. Is there any difference between them?
Yes, the I/Os are quite different. What will you be connecting this IC to?
I will most likely be connecting it to a motor driver, something similar to the chip you recommended in post # 22
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If you are not using PWM to control speed ,then there should be no problem.
I also found this chip, which seems to be similar to the chip you recommended, but again it is much cheaper. Could I use this product instead?
Thank you, I most likely will not need to control speed. Does this mean the motor will run at full speed all the time?
Yes, full speed
I also found this chip DRV8835DSSR. It the same as the one on the pololu board I cited
I did not realize that you were making a PCB so I was recommending off-the-shelf modules.