Micromanipulator

Micromanipulator
Essentials
Full name	Micromanipulator
Manufacturer	Leica/Zaber/Eppendorf
Description	Optical microscope + motorized stage + manipulator arm
Location	Basement, Elionix room; 03.01.K03
Responsibility
Primary	Karolis
Secondary	Martin

Micromanipulator is a setup meant for nanowire transfer from a source substrate to a target substrate. This is done using a transfer arm that can move with sub-micrometer precision. The substrates can be moved with a motorized stage in x, y, z, and rotated around the z axis. The action can be observed through a microscope/camera.

Usage rules

Do not place used probes back into the box. If you want to reuse a probe in the future, put it in your own box and clearly label the box. Unknown boxes will be disposed of.

Put used probes into the sharps bin. Do not close the sharps bin fully but leave a small gap to put probes.

Wipe all surfaces both before and after using the tool. Nanowires can be very toxic. They are small enough to get into human cells and damage their DNA. The length of the DNA molecule is ~5 um, and most nanowires used at this tool are small enough to damage this molecule.

III-V semiconductors that the nanowires can include can also be very toxic. Take care of your own safety and also the safety of your colleagues.

Try your best not to crash the microscope objectives into the substrate or stage. Let the staff know if this happens -- send a short message to cleanroom@nbi.ku.dk.

Usage guide

Most users have a specific use case for the manipulator. Therefore this short guide should only act as a guideline. There is no wrong way to use the tool!

The following instructions use the paradigm of fixing the focal plane and only changing the z position of the stage and the probe. It is entirely a matter of preference as it can be equally efficient to constantly change the focal plane to e.g. follow the probe movements.

Prepare for work

Put on gloves and wipe down all surfaces that you might touch: handrest, joysticks, stage, knobs.
Make sure the PC is working and the LAS software is running. If not, reboot and launch the software.
On the stage joystick: Long press 1 to home all axes.
Make sure the stage is at the lowest vertical position and then move it up at least two steps.
Place your source and target chips on the stage.
Turn on the light: only the green button on the right.
Increase the light intensity: turn the knob clockwise. The more light, the faster the camera can produce visible images.

Find the target and source locations

Use the knobs on the linear drives to quickly position the target chip under the microscope light.
Use the joystick to find the target location for the transfer. Place it in the center of the field of view.
Adjust the working distance of the microscope using the knob on the right.
Change to a higher magnification objective. Only touch the big ridged ring and not the objectives themselves. Adjust focus again. Repeat until the image is in focus with the highest magnification.
Long press 5 to save the stage position. This is the target position. To prevent accidents caused by unintended button presses, save it to 3 & 4 as well.
Do not touch the microscope focus from this point on. All further movements assume we know where the focal plane is at all times.
Repeat the procedure for the source chip. Instead of moving the microscope focus, move the stage vertically. You can do this by twisting the joystick.
Long press 3 to save the stage position. This is the source position.
Short press 5 to verify the target position. Adjust z if needed and save again. The stage repeatability in z is not exact, so there might be small inaccuracies.
Short press 3 to verify the source position. Adjust z if needed and save again.

Get the probe ready

Short press 5 to return to the target position.
Swing the transfer arm out and take out the probe holder.
Place a desired probe in the probe holder. The visible shank length should be comparable to the wire.
Adjust the probe holder to the desired angle.
Set the probe controller to coarse.
While watching the probe wire, carefully swing the arm back in. The wire should not touch the substrate. The arm/probe should not touch the objective. Move the arm with the controller if needed.
Change to the lowest magnification.
Use the controller to move the wire in the xy plane until you can see it in the field of view.
Move it down until the tip starts to move into focus. Then change to higher magnification and fine movement speed.
Change to x-fine and repeat the process until you are at the highest magnification and the probe is nearly touching the surface.
Lightly touch the surface with the probe.
Look at the controller and move up 30 um.
Long press Pos 1 to save the probe position. This is the probe approach position.
Move up 300 um more (or more if you have a large difference in substrate thicknesses). Long press Pos 2 to save the probe position. This is the transfer position. Save it to Pos 3 as well, just in case.

Ready

Now you are ready to transfer!
- Short press 3 moves the stage to source position.
- Short press 5 moves the stage to target position.
- Short press Pos 1 lowers the probe to approach position.
- Short press Pos 2 raises the probe to transfer position.

Done

When you are done transferring:

Short press Pos 2 to raise the probe and swing out the arm.
Take out the probe and put it in the yellow sharps bin.
Long press 1 to home the stage and take your substrates.
Log your work and any issues you noticed. Notify the staff if there's anything wrong with the setup or you're using probes from the last silver pouch.
Wipe down all surfaces that you might have touched: handrest, joysticks, stage, knobs.
Done!

Instrumentation

Manipulator arm

Transferman 4r controller

Eppendorf TransferMan 4r system
or a custom manual arm

Regardless of which arm is used, there are markings on the optical table denoting where it should be fixed.

The Transferman 4r offers 3 programmable positions and 3 programmable movement speeds. You should be very careful and only use the two faster movement speeds at low microscope magnification, and only when far away from the substrate vertically. Be conservative with selecting the saved positions, since crashing the probe into the substrate can ruin your work very easily. Both short instructions and full operating manual can be found online.

The optimal angle for the probe depends on the nanowire stiffness, substrate geometry and substrate surface properties. A good starting point is 15°.

Stage

Zaber stage joystick

The stage is a stack of Zaber motion modules:

X-JOY3	Programmable 3-axis joystick
X-LSM100A x2	2 linear stages, <3 um repeatability
X-RSW60C-E03	Motorized rotary stage
X-VSR20A	Vertical lift stage, <1 um repeatability

The modules can be moved directly using the knobs on each module. For the x/y stages the knobs increase/decrease velocity, single press decelerates, double press instantly stops. Rotation/z stages are moved one step per knob position.

The joystick should have these functions:

Key	Short Press	Long Press
1	Stop all axes	Home all axes
2	Send alerts* 1, 2	Send alerts* 1, 3, 4
3	Move to saved position	Save current position
4	Move to saved position	Save current position
5	Move to saved position	Save current position
6	Axis x low speed	Axis x high speed
7	Axis y low speed	Axis y high speed
8	Rotation low speed	Rotation high speed

The joystick functions can be changed through the Zaber console - 1 software.

Microscope

This is currently a Leica DM2500 MH microscope body, Leica MC170 HD camera and Leica acquisition software setup.

The field of view/depth of field/resolution of this setup is somewhat limited, but should be good enough for most users.

In fact, short depth of field lets you judge the relative vertical position between the probe and the substrate.

Probes

Probe dimensions in inches

Also known as needles. These are thin tungsten wire on a thicker nickel shank. We use 72X-G2/01 (0.1 um tip radius) and 72X-G2/025 (0.25 um) from American Probe. The taper model can be found in this handy chart: .pdf.

Troubleshooting

I can't get any light through the microscope!

Lamp turned off
Lamp turned on. Notice that the left button remains in the same position.

Someone probably switched the light source to back lighting. The microscope does not support this. Simply flip the up-down arrow button on the light source. Double check that the green power button is lit, and the knob is not at the minimum position.
The camera output is completely frozen!: Turn on live capture mode.
I would like to save an image of what I see but I don't know how!: Press Acquire image in the bottom left of the Leica software window.
Everything on the PC is frozen, I can't move the mouse cursor!: The PC has crashed. Find the power button on the PC under the optical table and hold it for several seconds until the PC restarts.
The image is very strange!: Maybe someone crashed the lens into the stage and did not tell anyone. Move the stage and the manipulator out of the way, carefully unscrew the questionable objective, blow away any dust with the nitrogen gun, and very gently wipe the lens with mild solvent. Original cleaning instructions from the manufacturer can be found online.
The image on the screen updates only every few seconds!: The automatic exposure function in the software collects enough light to see a good signal. Try to increase the light intensity by turning the knob on the power supply clockwise.
The image is too bright/dark!: There are two options:

Auto exposure

The automatic exposure fuction in the software is turned off. The iris button in the top left of the Leica Acquisition Suite window should be red: Acquire > Camera > Automatic exposure.
If it is already active and at the exposure limit, try adjusting the light intensity.

Ordering probes & service

This information is on the internal QDev wiki.

Remote access

TeamViewer: uManipulator
LogMeIn: uMANIPULATOR (K03A)