What is the Thermal TPM? The Thermal TPM is a device used to determine specific properties like the surface topography and thermal conductivity of any given material. The Thermal TPM if the result of a combined effort by 7 Engineers (including myself) to satisfy our 4th and final year project at University.

How does it work? The Thermal TPM is a system that contains several mechanical and electrical components all working in harmony to perform its required task. This system contains the following major modules:

• Aerotech Table - Provides precision motion on the X and Y axis
• PZT Motor - Provides precision motion on the Z axis
• The Tip - Point of contact between Thermal TPM and given material
• DAQ Card - Source of feedback and relayer of data between devices

The Tip is connected to the PZT Motor which is firmly positioned on the system and only capable of moving the Tip along the Z axis to make and break contact with the sample material. The sample material lies on the Y axis plane which in turn lies on the X axis. This arrangement allows the system move the sample material so the tip can be made to come in contact with any point on the surface of the material.

The diagram above is an example of the path taken by the tip along the surface of the sample material. The yellow point is the start point where the tip makes contact, after taking a reading it breaks contact and moves to the next point then makes contact again. This path is akin to the scanline used by some TV's. After a scan is made the data fed back to the PC via the DAQ card from the Tip is processed by the software and used to plot one of many graphs for visual interpretation.

What was your role? My role as the only Computer Systems Engineer of the group was not only to handle all aspects of communication between the devices and the PC but also to design and develop the final software that would contol all aspects of the Thermal TPM. I had my work cut out for me!

The picture on the left is the motor used to handle moving the Tip along the Z axis of the system. It's an N-214.00 NEXLINE High-Load Actuator capable of moving in both large and small steps; large enough to get the Tip to the material quickly and small enough to take readings on the nano scale. The picture on the right is the interface to the Data Aquisition card developed by National Instruments installed on the PC. This card would be used to control the various other electronic devices developed by my colleague and recieve feedback from them.

The final control software shown above was created via a collaboration of Dark Basic, C++ and 3rd party software. Dark Basic was used to handle the 3D user interface, C++ was used for low-level interfacing with the different devices and the 3rd party software was supplied by the manufactures of the off-the-shelf products for use in controlling their devices via the PC. The 3D interface, made to look uncanily like the real Thermal TPM system was used for its cognitive advantages. If the user had seen and used the real-life system then the transition to the virtual one would be easy. For example by clicking on a component, say the X axis plane, the user could control the X axis with the keyboard directional keys and as the virtual X plane moved so would the real X plane.