ArC One
ArC ONE hardware platform
ArC ONE Control user interface

Available Now.


ArC ONE is an ideal measurement instrument for working with crossbars of emerging non-volatile memory technologies. These include resistive memory, or memristors (RRAM), phase-change memory (PC-RAM), spin-transfer-torque magnetic memory (STT-MRAM), and others. A powerful hardware base coupled with an intuitive user interface that provides complete freedom for characterising single, or arrays of devices either directly on wafer or in packaged samples.

ArC ONE Control Software [2021-01-21]: v1.5.2 or v2.0.0-rc3 (pre-release)
Newer and prerelease versions are also available in PyPI. If you have Python ≥ 3.7 installed you can get ArC ONE with python -m pip install arc1_pyqt.

ArC ONE Firmware [2021-05-11]: v9.5 — Previous releases: v9.4 v9.3 v9.2 v9.1.4.2 v9.1.4.1 v9.1.3.4
Firmware installation/update instructions: To update the firmware download the latest version above, unzip it and copy the bin file in the MBED drive that appears when you connect ArC 1, replacing the old one. Then press the button on top of the board and wait until the LED stops flashing. Restart the interface.

User Manual: [PDF] [HTML]

Recent work enabled by the ArC ONE platform:

[1] A. Serb, et al. "Unsupervised learning in probabilistic neural networks with multi-state metal-oxide memristive synapses", Nature Communications, July 2016.

[2] I. Gupta, et al. "Real-time encoding and compression of neuronal spikes by metal-oxide memristors", Nature Communications, Sept 2016.


ArC One contains the full measurement capability for comprehensive resistive memory characterisation. An elegant, straightforward user interface makes this instrument accessible to any researcher, from undergraduate to post-graduate level and beyond. While fitting on a desktop, adding this instrument to your range of research tools alleviates resources in a shared laboratory and provides your team with a wider range of possible paths towards your research goal.

The current generation of ArC ONE includes I-V measurement and current cut-off forming. Unlike generic parametric analysers, our bespoke systems warrant current cut-off in maximum 20us, so you know what is the input to your device at any point in time. What you see is what you get. Our single thread execution on the master u-controller on-board ensures that pulse-widths and inter-pulse timings are accurate within 10 ns. Pulse amplitudes of up to ±12V with rise/fall times of down to 30 ns and pulse widths down to 90 ns capture the full range of resistive switching requirements.

Executing a variety of read and write protocols along with implementing advanced automated test modules becomes trivial. Furthermore, complex multi-device circuit topologies can be easily tested whilst measurement data is displayed in real time on a local PC/MAC. We also offer a service for developing any testing module to fit your needs.

ArC ONE connected to devices on wafer via a custom probe-card.


  • Linear resistor measurement: 100 Ω to 100 MΩ with <10% error; 220Ω to 10 MΩ < 5% error @ 0.5 V;
  • Linear resistor reading acquisition time: 20 ms;
  • Minimum current measurement: ±1 nA (<5% error @ 0.5 V);
  • Maximum current measurement: ±5 mA (<5% error @ 0.5 V);
  • Non-linear resistor maximum reading acquisition time: 700us - 1 ms.


  • Maximum pulse amplitude: ±12 V;
  • Voltage pulse resolution (0 - ±1 V): 3 mV;
  • Voltage pulse resolution (±1 V - ±12 V): 24 mV;
  • Current cut-off range: 10uA - 1000uA;
  • Minimum pulse width: 90 ns;
  • Pulse width resolution: 10 ns;
  • Maximum sourcing/sinking current: 50 mA;
  • Minimum READ -> WRITE interval: 120 us;
  • Minimum WRITE->READ interval: 100 us;

Crossbar management:

  • Supports up to 32x32 crossbars (1 kbit);
  • Four 2x8 headers support external connection;
  • Four BNC connectors expose the active/inactive word and bit lines;
  • A 86 pin PLCC slot allows packaged samples to be mounted and tested on-board;
  • Active multi-port current redistribution scheme;
  • V/2 and V/3 write scheme;

User Interface:

  • Python based - open source;
  • Read Single, Read All or Read Stand Alone capabilities;
  • Ability to select in between two read types;
  • Color coded resistance map of DUT crossbar, updates after any operation;
  • Click-to-pulse: apply single voltage pulse followed by a read operation;
  • Real-time view of resistance evolution, along with the history of the pulsing operations performed;
  • Pan, zoom and save publication-quality figures of the DUT history straight from the interface;
  • Record the history of applied pulsing modules/single reads/single pulses in a separate history log;
  • Expandable: new pulsing modules are added as separate unique files;

Master u-Controller: mBED LPC 1768:

  • 96 MHz Cortex M3 processor
  • on board DAC: 10 bit
  • on board ADC: 12 bit

ArC ONE comes with the following standard built-in modules: (can be applied automatically on 32x32 crossbar array, array subsets or individual devices)

  • Electroforming: Incremental step pulsed programming routine; stop when benchmark resistance level reached: Multistate programming;
  • Retention: Measure periodically for fixed overall duration:
  • SwitchSeeker: Assuming a bipolar device, apply voltage pulses of increasing width and amplitude of both polarities in order to extract the pulse parameters which elicits repeatable analogue RS. Repeatable analogue RS;
  • STDP: Perform Spike-Timing Dependent Plasticity measurements with your choice of pre- and post-synaptic voltage spike shapes and durations. STDP;
  • Volatility Testing: Quantify the short-term volatile behavior of presumably long-term non-volatile devices. Volatile RS;
  • SuperMode: Allows drag-and-drop buildup of chain of measurement procedures from the ones above, including single READ operations, single voltage pulses and time delays.



ArC ONE Control user interface
10 IV measurement cycles showing repeatable resistive switching acquired via the CurveTracer algorithm. Measurements taken by Simone Cortese. Devices manufactured by Maria Trapatseli.
Several analogue resistive switching cycles enforced by the SwitchSeeker algorithm
IV cycle switching with current cut-off @ 1mA
Pulsed ramp multistate programming via the FormFinder algorithm
STDP measurement example with similar pre- and post-synaptic voltage spikes.
Endurance with current cut-off during SET transition at -4V, 1mA.
6000 endurance cycles via the Endurance algorithm. Measurements taken by Simone Cortese; devices manufactured by Maria Trapatseli.
Example of analogue resistive switching via the SwitchSeeker algorithm
Short-term volatility characterisation
Static IV measurement example