# Control and Flow mechanics

1. Apr 3, 2013

### iii

1. How I can calculate the flow mechanics forces that operated on the wafer?
How I can calculate the stress, forces and torques that are permit to put on a wafer that his thickness is 100 microns and his width is 10 meter and his length is 10 meter.
The wafer is from the family of semiconductor material.
This is important that will not appear any deformation on the wafer.
What stresses are more or less important from this list in this case and why?
Stretching, pressing, shearing, twist, bending, sinking and collapse.
After I can calculate the permit (the maximum permit) of the stress, forces and torques I want to understand how to control this.
What kind of forces sensors and torques sensors to detect the touch have?
It is important don't touch the wafer in the process of producing it, so the sensors need to feel without to touch.

2. What is the connection between this gripper that is in the website that I added and Bernoulli equation and \ or aerodynamics of wings of airplane?
http://hydraulicspneumatics.com/200...ng/Article/False/87862/IndZone-FoodProcessing

3. I search information about accuracies sprinklers, with these sprinkles build these wafers.
What is the connection between sprinkle and flow mechanics?

4. I search after information about ways to cold the solar panel.
I know that there is one way to do it with hydraulic control system, but I don’t know a lot of this and I will glad to know more about this.

2. Apr 3, 2013

### etudiant

You've asked several times about the issue of managing thin sheets of semiconductor material. presumably for solar panels.
You need to get a better handle on the underlying technologies, because your questions conflate several different approaches, leading to confusion.
The problem is the size of the panel you are considering. A semiconductor wafer comes from a single crystal that has been sliced. The biggest crystals currently under consideration for production are about 0.45 m in diameter, but production volumes still only use smaller 0.2 m and 0.3 m wafers. Solar panels use a lot of these wafers linked together, a costly assembly process, for a 10 m unit.
There have been efforts to grow continuous ribbons of crystal as much as 20 cm wide, but afaik they have not become commercial and no one is selling them any more.
There are other solar power collector designs that use amorphous crystals, which can be deposited on a load bearing substrate to make big 10 m panels directly, at some sacrifice of efficiency. There is research under way to try to use printing techniques for laying down solar cells on a flexible substrate, but the progress is not yet sufficient to attract large scale investments.
The wafer handling challenges you focus on are because the wafers are brittle. Also, they are very easily contaminated until they are given a protective coating late in the manufacturing process. We do not have the know how to make really big wafers such as you envision, so there has not been any machinery developed to handle such large items. For instance, the gripper you give a reference to picks up items up to 60 mm across, a long way from the 10,000 mm wafers you mention.
So it would help if you could clarify what you would like to achieve.