Instant AFM and nanoprobe instrumentation - just add science! View our AFM Video Tutorial.

MadPLL phase lock loop controller for building tuning fork AFM with nanopositioning systems

MadPLL Atomic Force Microscope Image of a Test Pattern

MadPLL Atomic Force Microscope Image of an Integrated Circuit

MadPLL Atomic Force Microscope Image of a Fly Eye

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Introduction

MadPLL^® is a powerful instrument package that allows the user to create an inexpensive, high resolution resonant scanning probe microscope using Mad City Labs nanopositioning systems. In short, MadPLL^® can be used to create an “instant” closed loop AFM or NSOM at a fraction of the cost of commercial systems. MadPLL^® is suitable for nanoscale characterization and nanoscale fabrication applications such as optical antennas, nano-optics, semiconductors, data storage, and more.

MadPLL^® has been specifically designed for resonant probes such as tuning forks and Akiyama probes. In addition MadPLL^® is fully compatible with Mad City Labs’ high resolution nanopositioning systems which makes it easy for users to build a scanning probe microscope with a flexibility that cannot be achieved with other commercial systems. The seamless integration of hardware combined with the built-in automated control of MadPLL^® means that you can concentrate on getting results.

MadPLL^® is ideal for research and teaching laboratories offering high performance, versatility, simplicity and excellent value.

Features

Low cost
Software, PLL controller, sensor amplifier, and probe boards included
Easy and flexible configuration
Fully self contained - no external signals required
Automated software control

Auto PCC control
Auto Q Calculation, resonant frequency detection
Integrated Z axis PI control loop
Fully compatible with Mad City Labs positioning products

What is MadPLL^®?

MadPLL^® is an integrated solution that includes the digital phase lock loop (PLL) controller, software, sensor amplifier board and resonant probe mounting board. Simply add your Akiyama probe or tuning fork to the probe board to create a powerful force sensor for scanning probe measurements.

control schematic for MadPLL phase lock loop controller

The MadPLL^® package includes the MadPLL^® digital PLL controller, sensor board, probe board, and MadPLL^® software. Ease of integration with resonant probes and Mad City Labs' low noise nanopositioning systems give users the ability to create high performance, low cost NSOM and AFM instruments.

The PLL controller contains a digitally controlled proportional integral (PI) loop designed to work seamlessly with Mad City Labs’ nanopositioning systems. The addition of closed loop nanopositioners adds to the high performance of MadPLL^®. Additional options are available for multi-axis closed loop nanopositioning control.

The PLL controller has three operational modes: self oscillation, PLL driven, and (lock-in) DDS driven. The probe can be controlled in constant excitation or constant signal mode. Measured outputs from the controller include changes in frequency, amplitude or phase shift.

control schematic of MadPLL phase lock loop controller with constant excitation ampltude or constant probe feecback amplitude

The digital MadPLL^® controller has three operational modes: self oscillation, PLL driven, and DDS driven. The probe can be controlled in constant excitation amplitude or constant signal amplitude. Changes in frequency, amplitude, or phase are measured for Z control.

The MadPLL^® package includes a digital phase lock loop (PLL) controller, software, sensor amplifier board, and resonant probe mounting board. MadPLL^® includes five (5) each of the vertical, horizontal, Akiyama, and blank probe boards. In addition, each unit is shipped with five (5) tuning forks. Additional probe boards and tuning forks can be purchased separately.

The sensor amplifier and probe board assemblies are compact and can be fitted to existing instrumentation. The probe board simply plugs into the sensor amplifier board. The sensor amplifier board can be mounted to a precision positioner such as a closed loop nanopositioning system. The probe board has been designed for use with tuning forks and Akiyama probes. These probes are easy to mount and alignment free.

MadPLL^® includes a sensor amplifier board and probe boards. The probe boards are designed for use with tuning forks, Akiyama probes and Accutune probes.

MadPLL^® Software

MadPLL^® software simplifies the control of your scanning probe microscope. All of the functions of MadPLL^® are fully automated but accessible via individual software control. Among the software features are automated setup, configuration control, auto-Q calculation and automatic parasitic capacitance compensation (PCC) control. These included features are designed to simplify setup and accelerate the data acquisition process. MadPLL^® software integrates seamlessly with Mad City Labs' AFMView™ software. AFMView™ software is part of our complete SPM development system.

Application - AFM Video Tutorial

Instant AFM - just add science!

MadPLL^® can be used to create a customized, high resolution Akiyama probe or tuning fork atomic force microscope (AFM) at a fraction of the cost of commercial systems. MadPLL^® has been designed to directly interface with Mad City Labs’ low noise single and multi-axis nanopositioning systems, making it possible to create a fully closed loop AFM. The AFM described is suitable for both research and teaching environments and can be further customized for vacuum operation. MadPLL^® is suitable for nanoscale characterization and nanoscale fabrication applications such as optical antennas, nano-optics, semiconductors, data storage, and more.

Mad City Labs AFM Assembly Tutorial - How to Build an "Instant" Atomic Force Microscope

Video Bill of Materials

SPM-M Kit

MadPLL^® Instrument Package

digital phase lock loop (PLL) controller
Akiyama probe mounting board
sensor amplifier board

Nano-SPM200 nanopositioning stage (XY)
Nano-OP30 nanopositioning stage (Z)
3 axis closed loop Nano-Drive^® controller
Z axis open loop/close loop switch (OCL option)
Adapter plate between preamplifier and Nano-OP30
Adapter plate to Thorlabs MT1 micropositioner

XY and Z coarse motion: standard stages available from optical component suppliers
Probe: Akiyama probe
Hardware: standard optical mounting fixtures
PC: Windows XP/Vista/7 (32 bit or 64 bit compatible)

This configuration is a highly flexible, low cost, multi-axis, closed loop Akiyama or tuning fork AFM called the SPM-M Kit. All Mad City Labs nanopositioning systems have low noise PicoQ^® sensors and closed loop feedback control. Using MadPLL^® the user can create a high performance scanning probe instrument at low cost.

Additional options available from Mad City Labs

Quartz Crystal Tuning Forks
AFMView software (included with SPM-M Kit)
Other configurations of 3 axis closed loop nanopositioners*
(e.g. Nano-HS3 Series, Nano-OP30 (Z), Nano-H Series (XY))
Vacuum compatible nanopositioners
LED Illuminator
Tungsten tip etching kit

* All Mad City Labs nanopositioning systems include the Nano-Drive® controller which is fully LabVIEW/C++/MATLAB compatible.

AFM configurations typically achieve Z resolutions of 0.5nm (rms) and a scanning frequency of 1Hz. Higher resolutions and scan speeds can be achieved using different nanopositioner combinations. All Mad City Labs nanopositioning systems ahave low noise PicoQ^® sensors and closed loop feedback control.

Recommended additional items

Vibration isolation table
Coarse Z-axis approach (manual or automated)

Image Gallery

Seeing is Believing!

The images below were acquired using MadPLL^® with Mad City Labs closed loop nanopositioning systems.

	Calibration grid (100nm tall lines, 2µm apart) 10µm x 10µm Unidirectional scan Self oscillation mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-HS3 3-axis nanopositioning system.
	Calibration grid (100nm tall pegs, spaced 2µm apart) 10µm x 10µm Unidirectional scan Self oscillation mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-HS3 3-axis nanopositioning system.
	Fly eye 100µm x 100µm Bidirectional scan PLL mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-OP30 nanopositioning system (Z-axis), Nano-OP100 nanopositioning system (XY axes)
	Human hair 100µm x 100µm Bidirectional scan Self oscillation mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-OP30 nanopositioning system (Z-axis), Nano-OP100 nanopositioning system (XY axes)
	PMMA pattern, uncured 10 µm x 10 µm Bidirectional scan Self oscillation mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-OP30 nanopositioning system (Z-axis), Nano-OP100 nanopositioning system (XY axes)
	Integrated circuit 100 µm x 100 µm Bidirectional scan Self oscillation mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-OP30 nanopositioning system (Z-axis), Nano-OP100 nanopositioning system (XY axes)
	Calibration grid 40 µm x 40 µm Unidirectional scan Self oscillation mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-OP30 nanopositioning system (Z-axis), Nano-OP100 nanopositioning system (XY axes)
	Calibration grid (100nm tall, 10µm pitch) 70 µm x 70 µm Unidirectional scan PLL mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-OP30 nanopositioning system (Z-axis), Nano-OP100 nanopositioning system (XY axes)
	Etched structures 80 µm x 80 µm Bidirectional scan Self oscillation mode, constant probe signal Z force feedback: frequency Data taken using MadPLL^® with Nano-OP30 nanopositioning system (Z-axis), Nano-OP100 nanopositioning system (XY axes)

Technical Specifications

Lock-In Amplifier
Phase Shifter	0° to 360°
Demodulation Bandwidth	3 kHz

Phase Lock Loop
Auto Range Selection	YES
Measurement Range	± 500 Hz
Measurement Resolution	50 mHz

Preamplifier
Input Gain (Attenuator)	0x to 1x (16 bit internal DAC)
Parasitic Capacitance Compensation (PCC)	YES
Automatic PCC	YES

Probe Oscillation Loop
Operating Modes	self oscillation PLL driven lock-in/DDS driven
Amplitude Control Modes	constant excitation constant signal
Amplitude Setpoint	16 bit internal DAC
Amplitude Control	YES, adjustable PI loop filter
Input Voltage Range	±10 V(peak)
Input Voltage Gain	2x to 40x
Frequency Range	10 kHz to 100 kHz
Output Voltage Range	±10 V(peak)

PI Loop Filter (Z-Axis)
Integration Time Constant	digitally controlled
Digitally Set Parameters	YES
Error Signal Inversion Capability	YES
Sensor Signals	frequency phase excitation amplitude signal amplitude
Command Signal	16 bit internal DAC
Automatic Loop Filter Setup	Yes, after initialization
Loop Output	0 to 14V

General
Spectrum Analysis	amplitude, phase
Feedback Monitor BNC	frequency phase excitation amplitude signal amplitude
Probe Signal Monitor (BNC)	sinewave amplitude probe (diagnostic)
Power Supply	90 to 260 VAC (50/60 Hz)
Controller Dimensions	16.75" x 14" x 1.75" (1U) (42.55cm x 35.56cm x 4.45cm)
PC Connection	USB
Operating System	32 bit: Windows 2000/XP Pro/Vista/7 64 bit: Windows XP Pro/Vista/7
LabVIEW Software OS	32 bit: Windows 2000/XP Pro/Vista/7 64bit: Windows XP Pro/Vista/7

Additional Information
MadPLL^® Brochure	Laser Focus World Article NANOPOSITIONING: Piezoelectric nanopositioners forge low-cost atomic force microscope	AFM Video Tutorial
MadPLL^® Sensor Probe Board Drawing