Pressure sensor at the microscale

[BigBeard]

Hello all,

I am looking for a probe that detects force and converts it to a pressure reading. I would be using it for measuring the pressure of single cells of a multicellular organism, at specific points on the cell, So we are talking about a pressure sensor attached to a micro or nano pipette, with a sensor attached to the tip no larger than 10-20 microns. If anyone could guide me in the right direction or give me any advice, it would be appreciated.​

 

[VEBill]

Anything in this field applicable?

https://en.wikipedia.org/wiki/Atomic_force_microscopy

 

[amorrison]

There are pressure sensors that can control to 1 Pa.
They can control the airflow (HVAC)through an open doorway.
Recall 1 ATM = 1.03 x 10^^5 Pa so this "pressure" is next to nothing.
Googling "Pa" or force and sensor will probably get you what you want.

 

[BigBeard]

Ve1BLL, thanks for the advice, but an AFM would have to be heavily modified to suit my needs; but more importantly, I do not have one of those. The principles are there, but I would need to invest a lot of time into making it suitable for my needs, and even finding someone that would allow me to modify their equipment. I only hope that there is a much easier solution, such as a membrane pressure sensor place on the tip of a probe with a micron diameter. Then that could just connect to an amplifier to give me readings.

Amorrison, I have searched and found a few companies, some of which I still have to call, and others of which must get back to me. The only problem is that their sensors are not on a small enough probe to be useful for me. It is not only about sensitivity, but size is also very important.

I just though someone here would have come across something similar to what I am looking for.

 

[gruntguru]

You probably need to supply more information - anticipated pressure for one thing.

How do you propose to seperate the force applied in manipulating the probe (which will have to be reacted by contact with the organism) from internal pressure of the organism? Can you puncture the organism allowing the pressure to be sensed at right angles to the probe force?

One alternative is to use a passive probe tip of known geometry and measure force vs displacement as the probe contacts the organism. This will give you a pseudo "elastic modulus" for the region being investigated.

Link

5 x 10^-9 N (resolution of the smallest sensor in the link) on a tip 20 uM diameter is equivalent to 16 Pa.

je suis charlie

 

[BigBeard]

gruntgury, thank you for the post. It seems like that company may have what i am looking for. I will be in contact with them, and will let you all know the outcome.

 

[Compositepro]

Pressure is a term that only applies fluids. When solids are around it can get pretty complicated to define what is meant by the term pressure. You might be able to use a force balance technique such as using a hollow glass fiber with a fluid in it. when the pressure at both ends of this tube are the same the fluid flow in the tube will be zero.