Cryo-walking technology

The cryo-walking technique

A game changer in cryogenic nanopositioning

Cryo-walking is the novel and alternative cryogenic nanopositioning technique compared to slip-stick. Where slip-stick depends on the static and dynamic friction differences, cryo-walking can actively make and break mechanical connections between slider and piezo material. This means you can effectively perform continuous scanning with a shear piezo that is allowed to be resetted at the end of its stroke without being contact with the slider. This comes with various benefits from extreme low heat dissipation, stiff design, high payload capabilities, to doing sub-nm positioning over the full millimeters travel range.

Capacitance-based position sensing

Reliable position encoder for low temperature environments

When selecting a good position sensor, some of the criteria to consider are measurement resolution, heat dissipation, sample rate, ease of integration, calibration procedure, and cost. We concluded a capacitance-based position sensor is the obvious choice for low temperature position sensing. A sensor that is more accurate, more reliable, and dissipates less than a resistive sensor. And, a sensor that is easier to integrate and calibrate, cheaper, and dissipates much less than an interferometer. Our position sensors are integrated by default into our cryogenic nanopositioners. It was never simpler, switching to closed-loop operation.

Long range cryo-positioning
preserving milli-Kelvin temperatures

Extreme efficiency in positioning at low temperatures

Positioning at milli-Kelvin temperatures is a key enabling technology for studying novel quantum materials and devices. Most quantum states are only visible and controllable when the thermal energy k_{B}T is comparable or smaller than the energy difference ΔE between the quantum states. Therefore, to see the quantum properties of materials or devices, they often need to be cooled to and maintained at temperatures between 10 mK and 300 mK. In this field it is of great importance to have the ability of doing positioning of (quantum) sensors over materials, alignment of optical components, and other R&D tools, while preserving the low temperature conditions. However, the cooling power at these temperatures is often in the order of micro-Watts, while most conventional large range positioning solutions produce milli-Watts of dissipation at their minimum operating frequency and as such increases the temperature of the refrigerator. In this white paper we show that arQtika, the cryogenic nanopositioner of Onnes Technologies, dissipates in the order of micro-Watts, resulting in a significantly more stable thermal milli-Kelvin environment while positioning, i.e. minimizing drift and thermalization times.

Download Whitepaper