ICnano Specifications
System
Magnification: 1,000x - 100,000x
Scan resolution: 20nm XY; 5nm Z
Scan time: 50s - 20min (typical, 5 µm x 5 µm and 90 µm x 90 µm respectively)
Image resolution: 128x128 - 1024x1024 pixels
Image formats: IMG (16-bit greyscale); PNG; PSD (Photoshop)
Scan head
XY scan
Range: 100 µm x 100 µm
Resolution: 20nm overall (1nm for stage)
Linearity: 1%
Maximum pixel step rate: 1ms per pixel
Z scan
Range: 100 µm
Resolution: 10nm or 5nm overall (1nm for stage)
Pipette
Tip diameter: >50 nm borosilicate; >10 nm quartz
Typical surface proximity: 50-100 nm for 100 nm dia; 10-20 nm for 20 nm dia
Body diameter: 1 mm
Positioning
Range: 15 mm XY; 25 mm Z
Resolution: 100 nm
Amplifier
The ICnano® SICM is supplied with an Axon Instruments CV-5 1GU headstage amplifier to buffer the low current signal from the scanning pipette. However, if an external amplifier is to be used, e.g. for patch clamping, it may be connected instead.
Feedback resistor: 1 GΩ
Noise: 25 μV/Hz typical at 10 KHz
Input bias current: 1 pA max at 25 °C
Power supply: ±12 V
Electrodes
Pipette: silver/silver chloride wire
Bulk electrolyte: silver/silver chloride pellet
Scan head assembly
Translation stage: Physik Instrumente PI Hera P-6xx, 100 µm; PI LISA P-753, 25 µm
Motorised positioning: Physik Instrumente M-111/112 DC motor translation stages
Overall dimensions: Approx. 13cm (W) x 17cm (D) x 15cm (H)
Controller
DSP module
Innovative Integration, SBC6711, 32-bit, floating point, 250 MHz single-board computer, using TMS320C6711 DSP, with A4D4, four channel, 16-bit I/O module.
Piezo-electric driver
PI, E-500 modular amplifier system.
Software
Scan setup
The pre-scan user interface provides straightforward access to all scanning parameters, both basic - scan mode, type
, resolution, XY range, offset and height range - and fine tuning - gain, convergence, threshold and modulation. Scan modes and types include single scan, continuous scanning, topography, ion current and second channel (e.g. fluorescence).
Scan management
During an active scan, the system displays scan progress in real time. For each parameter (topography, ion current and second channel), a window shows a progressive greyscale image and a profile of the current line (including line number and peak-to-peak height), along with any setup parameters that may be adjusted during the scan for fine-tuning.
Once the scan is complete, the image is processed to normalise the scan lines. The image may be examined, and saved if desired. If an area of interest is zoomed for closer inspection, the system prepares automatically a set of scanning parameters to enable a subsequent, higher resolution scan of that area. If the ICnano® is operating in continuous scan mode, the image is saved using an incrementing filename and the next scan is started automatically.
Image processing
ICnano® has a comprehensive set of image manipulation tools, designed to aid the analysis, exploration and presentation of scan data. Two separate channels of data, e.g. topography and fluorescence, may be combined in a variety of ways for display and analysis. The same software tools may be used also to work with bitmap data from other sources.
Global tools include zoom, brightness, contrast, false colour and colour palette. Retouch tools include scan line and area removal. Other global adjustments include slope correction and de-striping. A comprehensive and flexible set of spatial filters is provided, including smoothing and edge enhancement, along with FFT and de-convolution.
Local analytical tools include spot, length, area and volume measurement, profile along an arbitrary line (straight and freehand) and roughness.
Topographic data is stored in "top view" greyscale form. However, a rich set of 3D surface manipulation tools are provided. For speed, real time editing is carried out on a 256x256 pixel version of the image. Once committed, the full resolution image is processed. Facilities include scaling, rotation, elevation, flexible illumination, contouring and imposition of a second data channel onto the surface.
For presentation purposes, scan data may be formatted in a broad variety of ways, with supporting scales, legends, keys, annotation, colouring and background. Individual scans may be grouped in an "image stack" for consistent preparation or for display in an animated sequence. Original scan data may be displayed in a pseudo-live-scan.
System requirements
The software has been tested under Windows 98, 2000 and XP operating systems. Interface with the controller is via USB. The scanning system makes few demands of the host processor or memory. However, for best image display and manipulation, the PC configuration should include a minimum of 128 Mb RAM and a 1024x768, 32-bit graphics adapter.
