VS-STYLUS Constant Distance SECM

• STYLUS is developed and supplied through exclusive partnership with SENSáSION, EPFL
• Eliminates many of the experimental difficulties of Approach Curves and changing probe-to-sample distance that are associated with standard SECM techniques

The VersaSCAN Scanning Electrochemical Workstation is a single platform capable of providing spatial resolution to both electrochemical and materials-based measurements.  This system integrates a positioning system, measurement instrumentation and probe to provide local information.  Traditional electrochemical experiments measure an average response over the entire electrode, electrolyte interface.  Rarely is a sample homogenous.  Samples often consist of local sites of passivate or active nature and sites of anodic or cathodic character.  This need to investigate localized phenomenon led to the emergence of scanning probe electrochemistry.

Positioning System:

• VersaSCAN is unique in the use of piezoelectric motors to drive the stages on all axes.
• Piezos are materials that move with very high precision, accuracy, repeatability but over small distances.  We use them to drive stages; therefore we reach a combination of scan area and scan resolution that is unmatched.
• AFMs do not move with the same scan range (usually piezo-element only; without the stage)
• Alternative positioning system designs use step motors, exclusive or as a basis for a hybrid system, and cannot move with the same resolution.

System Installation and Training:

This is full ‘white-glove’ service. An experienced team member arrives on site – unpacked the instrumentation, assembles, levels the system.  A developed checkout procedure is executed on a test sample to verify the system (installation).  The fundamentals of the technique are covered.  The users are trained to execute the same test (training).

Multi-Technique platform:

The VersaSCAN platform offers the ability to leverage the positioning system and software as common components for other scanning probe techniques.  The best-in-class measurement characteristics of AMETEK equipment combines with this unique positioning system for high-resolution measurements even at large areas.

In collaboration with SENSàSION, we are pleased to offer the Soft Stylus Probe contact mode technique developed by Professor Hubert Girault and co-workers of the Laboratory of Physical and Analytical Electrochemistry (LEPA) at the École Polytechnique Fédérale de Lausanne (EPFL) for constant distance SECM. The probe technology offers the following benefits:

• Constant distance SECM: SECM imaging without major topographic artifacts. Ideal for tilted, corrugated and rough samples.
• Soft contact with sample: with a contact force up to 1000 times less than hard probe technology, soft probes are ideal for studying biological samples in constant distance mode SECM.
• Low cost: no need for additional hardware and special feedback control electronics to control vertical position of the probe with respect to the sample.  Lowest cost constant distance SECM method available on the market
• Faster measurements: no need to measure topography before SECM scans. Fast approach curve to find the sample surface.
• Flexible and stable Probes: no risk of damaging the probe or sample during positioning and scanning.
• Small tip-to-substrate distance is easily achieved, greatly enhancing contrast imaging and improving image resolution.
• Easy Electrode Preparation: The tip of the electrodes can be cut after each use ensuring a clean surface. Replacement probes can be purchased.

VersaSCAN Positioning System

Specifications	VersaSCAN Base (VS-BASE)
Positioning System Range	X-axis:  100 mm Y-axis:  100 mm  Z-axis:  100 mm
Positioning Motor Technology	X-axis:  Piezoelectric motors,            no stepper-motor Y-axis:  Piezoelectric motors,            no stepper-motor Z-axis:  Piezoelectric motors,            no stepper-motor

STYLUS Measurement Technology

Specifications	VersaSTAT3	VersaSTAT3F
Max Current Output	±2 A (standard) up to ±20 A	±2 A (standard) up to ±20 A
Compliance Voltage	±12 V	±12 V
EIS Capability	1 MHz, Option	1 MHz, Option
Min Current Range	± 200 nA (6 pA resolution) down to ±4 pA (122 aA)	± 4 nA (122 fA resolution) down to ±4 pA (122 aA)
E and I Filters	200 kHz to 1 kHz,  including None	200 kHz to 1 Hz,  including None
Grounding	Grounded, Earthed	Floating, Isolated
Soft disposable electrode		Approximately 100 SECM experiments per probe
Electrode material		Carbon paste
Electrode body material		PET with Parylene C coated
Electrode Diameter		20 µm (typical)
Minimum tip sample distance control		Up to 3 µm
Modes of Operation		Constant Height Constant Distance
Probe Contact Pressure		Approximately 2.55 x 104 N m-2