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Nanopositioner

Introduction

Highly accurate positioning systems are integral for semiconductor manufacturing. Right now the HackerFab uses a custom version of the Open Micro-Manipulator with additional support for rotation, heating, and vacuum.

Goals

Feature

Objective

Positional Resolution

<1um

Global Positional Accuracy (e.g. repeatability of 0,0 after restart)

~5um after homing.

Rotational Resolution

1/12 deg resolution

Global Rotational Accuracy

1/2 deg resolution

Heating Range

50 - 200 degrees Celsius

Heating Accuracy

0.5 degree Celsius

Vacuum Strength

50mN of holding force

CMU Progress

2026 - Spring

Goal Status

Feature

Objective

Status

Positional Resolution

<1um

~1um resolution but highly affected by vibration

Global Positional Accuracy (e.g. repeatability of 0,0 after restart)

~5um after homing.

Not scientifically measured.

Rotational Resolution

1/12 deg resolution

<= 0.01 deg

Global Rotational Accuracy

1/2 deg resolution

Not scientifically measured.

Heating Range

50 - 200 degrees Celsius

Tested up to 150 degrees. Not externally validated.

Heating Accuracy

0.5 degree Celsius

0.5 degree accuracy up to 150 degrees (higher not tested). Not externally validated.

Vacuum Strength

50mN of holding force

58nM of holding force

Summary

During Spring of 2026 the CMU nanopositioner team was able to produce a working integrated system that contained all general features including 3 DOF movement, rotation, heating, and vacuum. However, there are still 3 main issues with the current implementation:

  1. Vibration resilience

  2. Packaging and Setup

  3. Firmware reliability

Vibration Resilience

Due to the nature of moving at sub-micron levels the micro-manipulator is extremely sensitive to vibrations. The above gif was taken at a 10x object lens where each line is ~2um wide. As you can see the movement is significantly larger than the goal of 100nm movement accuracy.

We have many theories about what could be causing it but have not done enough scientifically rigorous testing. We were able to greatly improve the vibrations with tennis balls but it was not enough.

To analyze the vibrations and we used an opencv flow detector; however, we are limited by the fps of the recording camera.

Packaging And Setup

The current micro manipulator took over a month to be built and is very susceptible to things getting unplugged/twisted/broken/etc. The system should be more robust to handling and easier to put together

Firmware Reliability

Right now there are various firmware reliability issues which could be improved. They do not stop the device from functioning but make it harder to use and less reliable. So far we have found the following issues:

  • Axis "freezing". Sometimes one of the axes will stop responding to commands

  • Bad nano-positioner homing. Sometimes after homing a axis it will not respond to commands

    • This might be related to the above "freezing" issue

  • Improper rotation homing. Sometimes if the rotation stage is really out of alignment it will fail homing

    • This should be resolved but still to be fully tested

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