Electrochemical atomic force microscopy device

Electrochemical atomic force microscopy device: 1) non-resonant sinusoidal-oscillating imaging mode (nroIM): a. Pure vertical z-modulation of the cantilever; amplitudes (from < 1 nm to > 250 nm) and frequencies (from 125 Hz up to 2 kHz) freely selectable. b. In each contacting cycle, a direct determination of the maximum contact force (force setpoint) takes place in real time, where upon all control parameters are automatically and continuously optimized. Force setpoint minimum down to 10 pN. Stable imaging also for "negative force setpoints", i.e., below the baseline of the free force curve. c. Effective line rate >= 2 Hz at 512 pixel/line for all force setpoints possible. d. Suited for cantilevers with spring constants from < 0.001 N/m to > 500 N/m. e. Topography, DMT modulus, adhesion, energy dissipation, force setpoint error and deformation are measured and displayed simultaneously (location and time) and in real time. f. Lateral resolution down to atomic defects in lattice is possible. g. The tip-sample force interaction is continuously displayed in real time during the imaging process. h. This mode can be operated without any limitation of functionality with liquid cells, heating cells, EC cell, etc. The change of deflection signal due to cantilever drift is automatically and continuously eliminated (drift, e.g., induced by change of temperature or other environmental conditions). 2) System should be temperature controlled to minimize thermal drift: sensor in scanner and bridge with feedback loop to have scanner + bridge at similar temperature. Availability to heat from ambient to 35 deg. C. 3) System must be: a. Low-z-noise (< / = 40 pm RMS) atomic force microscope (AFM) with closed-loop tip-scanner (in all 3 axes) >= 85 um x 85 um x 9.5 um XYZ. b. Large sample space, capable to integrate heavy (> 5 kg) additional components (e.g., Nanoprober, customized sample holders, external magnetic fields). c. Motorized 150 mm x 150 mm sample stage. d. Extensive set of resonant, non-resonant and non-resonant oscillating imaging modes. The non-resonant, sinusoidal-oscillating imaging mode (nroIM) with freely selectable i) pure vertical z-modulation of the cantilever (amplitudes from < 1 nm to > 250 nm) and ii) frequencies from 125 Hz up to 2 kHz, WITH automated, continuous contact force dependent imaging gains optimization. e. Enhanced scan parameter optimization algorithms that continuously monitor and automatically optimize key feedback-loop parameters (gains, setpoint) for all 3 imaging modes (contact, resonant and non-resonant oscillating). Algorithms are also based on a trace-retrace correlation score. User sets scan size, scan rate and pixel density, then selects engage and system sets and automatically controls feedback settings during scanning continuously. f. Extensive set of piezo force microscopy (PFM) imaging and spectroscopy modes volume spectroscopy (hyperspectral mapping modes) of PFM signals (frequency sweep on large bandwidth to get contact resonance frequency and eigenmode (amplitude/phase versus voltage) simultaneously to topography and mechanical properties, further referred to as dataCUBE modes. g. Torsional resonance mode to acquire dynamic friction signal. Mode has proven to high-resolution image moire pattern of stacked 2D materials. h. Nano-electrical imaging of surface potential (KPFM) in non-resonant, sinusoidal-oscillating imaging mode. 4) Sample handling and automation: a. Accessible sample space >/= 150 mm x 150 mm x 18 mm XYZ, up to 45 mm height. b. Motorized (minimum 150 mm x 150 mm) and programable sample stage, with vacuum sample hold down. c. Vertical, software controlled and automated AFM-tip engage functionality.

Bruker’s Dimension Nexus atomic force microscope (AFM) is the only instrument that fulfills the full combination of requirements. The key differentiator is Bruker’s patented oscillating, non-resonant PeakForce Tapping (PFT) mode, which is unique to Bruker (EU patent EP1938040A2) and underpins a family of advanced AFM capabilities. PFT enables non-resonant imaging in liquids and direct force control of the tip–sample interaction, which together are critical for stable, high-fidelity measurements in electrochemical environments. PFT originated from patented high-speed mechanical property mapping (US 7,658,097) and has expanded to include ScanAsyst (US 8,650,660), PeakForce QNM (US 8,646,109), and PeakForce Tapping control (US 8,739,309). These innovations allow users across experience levels to image with precise force control and simultaneously access nanometer-scale mechanical and electrical property information. PFT has also been extended to electrical modes such as PeakForce TUNA and PeakForce KPFM, broadening its applicability in operando electrochemical and nanoelectrical studies. For electrochemical AFM, PFT’s non-resonant operation is especially advantageous. In liquid environments where temperature, humidity, and media changes shift cantilever resonance, PFT avoids the need for continuous tuning, improving stability and reproducibility. It enables the use of softer cantilevers, increasing sensitivity to subtle surface changes. PFT simultaneously captures and displays, in real time, topography and multiple mechanical parameters (e.g., DMT modulus, adhesion, dissipation, force error, deformation), which is vital for monitoring dynamic processes during electrochemical reactions. Thermal stability is another essential factor for long-duration experiments. Nexus provides temperature control to maintain scanner and bridge at similar temperatures, minimizing thermal drift that would otherwise compromise repeatability in changing environments. Bruker also supports non-resonant, sinusoidal-oscillating Kelvin probe force microscopy (KPFM) in liquids using proprietary probes, extending quantitative nano-electrical characterization under operando conditions. Mechanically, Nexus employs a pure tip-scanner architecture. This is particularly beneficial in larger-volume electrochemical cells, because only the lightweight tip and scanner move. The sample—and any attached electrodes, contacts, or EC-cell hardware—remains stationary, preserving scan speed, feedback quality, and tracking accuracy even with heavy or complex assemblies. The instrument’s large, open geometry around the tip and motorized, programmable stage supports varied sample sizes and the integration of auxiliary hardware (probers, electrical contacts, magnetic fields, liquid handling, etc.). The stage’s automation enables precise repositioning without manual intervention. These features are especially impactful for glovebox operation. With limited physical access, Nexus allows users to move EC cells between scanning and electrolyte-addition positions purely via motorized control, maintaining engagement during immersion and avoiding trapped air bubbles. The generous space around the tip/sample area minimizes handling difficulties while wearing gloves and simplifies the use of accessories. Ease of use is further enhanced by a dynamic, real-time algorithm for automatic feedback adjustment, similar to continuous autofocus. This self-optimizing control helps establish consistent imaging parameters across different samples and can be applied to all topographic AFM modes (contact, tapping, and PeakForce Tapping). It is particularly valuable for novices, routine workflows, semi-automation, and fluid environments. For nanoelectrochemical and nanoelectrical experiments in liquids, Nexus supports specialized nanoelectrode probes that are embedded and robustly contacted within a glass carrier for safe handling and stable electrical connectivity—an approach well suited to glovebox use. When paired with PFT’s low-force, gentle interaction, these probes enable long tip lifetimes and electrochemical resolution better than 100 nm. These probes and associated capabilities are Bruker intellectual property. Aalto University’s EMI research group requires instantaneous, real-time correlation of topography with mechanical and, when needed, electrical parameters, during exposure to varying liquids and gases. Their work in batteries and electrocatalysis emphasizes mechanistic insights into energy materials and interfaces through advanced operando and ex-situ characterization, including battery aging. For such studies: Real-time, non-resonant imaging that avoids cantilever retuning is essential as environmental conditions change. Simultaneous capture of topography and mechanical properties is required at sufficient speeds to observe subtle, transient phenomena. Soft cantilevers are needed to detect small variations in morphology and mechanical response reliably. Nanoelectrode probes are necessary to interrogate nanoelectrochemical and nanoelectrical surface behavior. A tip-scanner architecture is preferred to keep samples stationary in liquids, preserving measurement fidelity. Thermal control to suppress drift between the scanner and bridge is mandatory for repeatable long-term experiments. Bruker’s Dimension Nexus uniquely satisfies these combined needs. Its patented PFT platform delivers stable, non-resonant imaging and direct force control in liquids; enables concurrent mechanical and electrical mapping in real time; supports advanced electrochemical workflows with glovebox-friendly ergonomics and automation; and provides the thermal and mechanical stability necessary for high-precision, long-duration operando studies. As such, Nexus is the only AFM that matches all specified requirements and is the optimal choice for the EMI group’s research objectives.