Atomic force microscopy (AFM) is widely used in industrial nanometrology and scientific research. However, its high sensitivity to environmental and structural vibrations often introduces stripe-like artifacts, which compromise measurement accuracy. Conventional solutions—including passive isolation, image-domain denoising, and methods that attach auxiliary sensors to the sample or stage—are limited by mechanical path mismatch, extra vibration channels from the sensors themselves, and the risk of filtering out genuine surface features. To address these issues, this article presents an integrated Hinged dual-probe AFM. The design integrates an imaging probe and a squeeze-film damping-based vibration-sensing probe on a single mechanical structure, combined with a signal-to-noise ratio-guided differential denoising algorithm. Experiments conducted under both single-frequency and mixed-frequency vibrational disturbances show that the proposed system effectively suppresses periodic artifacts and improves measurement fidelity.

Mid-infrared photothermal microscopy is an emerging technique that combines chemical specificity and non-invasiveness, holding great potential to complement the limitations of high-resolution fluorescence imaging. However, its sensitivity and signal-to-noise ratio are often compromised by the inherently small molecular absorption cross-sections. To address this issue, this study proposes a photothermal vibrational enhancement substrate that significantly enhances analyte infrared absorption through a multilayer thin-film design incorporating impedance matching and interference optimization. It effectively converts optical energy into heat within the sample region while suppressing thermal noise from the substrate. Experimental results demonstrate that the cavity-enhanced substrate leads to an approximately 10-fold increase in the longitudinal thermal amplitude. The substrate provided broadband enhancement across the 1400–1900 cm−1 range for various mid-infrared absorption materials. Furthermore, mid-infrared photothermal vibrometry spectrum and imaging experiments confirm the promising application of this technology in chemical imaging of trace and ultrathin samples. This work breaks through the limitations of traditional purely optical enhancement strategies and offers a new pathway toward highly sensitive, high-spatial-resolution, and non-destructive infrared photothermal imaging.

HYPOTHESIS:The electrical double layer (EDL) at solid-liquid interfaces provides a natural transduction pathway for understanding interfacial electrical properties without physical signal conversion and convolution. However, the EDL's ultrashort characteristic length and complex signal decoupling pose challenges for conventional techniques in achieving reliable measurements. Moreover, a critical gap remains in the underlying measurement theory. We hypothesize that a measurement platform combining EDL-mediated localized charge characterization with quantitative electrokinetic modeling can open new avenues for advancing interfacial science. EXPERIMENTS:We developed a force-controlled scanning ion conductance microscopy (FCSICM) platform that enables high-resolution mapping of interface charge distribution. The ion current rectification (ICR) sensitivity was systematically evaluated across diverse interfacial conditions, including bias voltages, substrate polarities, and electrolyte concentrations. To bridge these observations and theories, a physically interpretable electrokinetic transport model was developed. Furthermore, the platform's versatility was demonstrated on diverse patterns and structures, where the high-aspect-ratio microgrooves are inaccessible to most conventional scanning probe microscopy tips. FINDINGS:Force-feedback ensures stable probe-EDL engagement. The ICR results reveal a pronounced dependence of FCSICM on interfacial conditions, with the rectification ratio peaking (IPDL/IGlass = 1.5) at higher bias voltage (±1 V) and lower concentration (1 mM) due to Debye length expansion and enhanced ionic selectivity. The quantitative electrokinetic model faithfully reproduces current-voltage characteristics (RMS error = 0.009), transforming ion rectification from qualitative observation into a quantitative analytical tool. Synchronous topography and surface charge mapping across engineered substrates yielded excellent consistency, clearly differentiating distinct material interfaces. These findings collectively establish FCSICM as a promising tool for understanding interfacial science.

Simultaneous mechanical mapping and high-resolution topographical characterization yield rich compositional information for materials and biomaterials. The off-resonance tapping (ORT) mode in atomic force microscopy (AFM) offers an effective means to achieve this dual functionality. Nevertheless, ORT mode suffers from substantial closed-loop delay and limited robustness, leading to low imaging speeds that hinder its application in studying dynamic specimens. To address these limitations, we developed an integral off-resonance tapping (I-ORT) mode that replaces conventional fixed-point sampling with integral sampling of the interaction curve above the baseline. This method mitigates unpredictable interference from probe-sample interactions while maintaining the same drive and sensing conditions. As a result, I-ORT increases the ORT scanning speed by at least 10-fold without compromising mechanical property characterization. This advancement provides enhanced support for high-end nanotechnological research.

Acoustic tweezers operating at ultra-high frequencies (UHF, ⩾100 MHz) enable precise manipulation of micrometer-scale objects. However, higher frequencies intensify acoustic streaming, producing an additional drag force that complicates the prediction of manipulation forces and undermines stable manipulation. Quantitative characterization of acoustic streaming fields at UHF remains challenging because suitable microscale probes that minimally perturb the acoustic field are scarce. In this work, we investigate the feasibility of using impedance-matched GelMA hydrogel microspheres as soft probes to characterize acoustic streaming in UHF acoustic tweezers. Finite element analysis was conducted to assess the influence of a 50 μm-diameter GelMA microsphere on both the acoustic pressure and streaming fields. Furthermore, the acoustic radiation and hydrodynamic drag forces acting on the microsphere were quantitatively evaluated, enabling estimation of the average streaming velocity near the acoustic focus. The results suggest that GelMA microspheres offer a promising approach for indirectly quantifying acoustic streaming effects in ultra-high-frequency acoustic manipulation systems.

Scanning ion conductance microscopy (SICM) imaging quality is highly sensitive to experimental conditions. However, conventional feedback control typically relies on empirically chosen current-decay thresholds, limiting robustness and transferability across environments. To overcome this limitation, we present a novel force-feedback SICM system whose core method is an adaptive pre-scan calibration procedure. The probe approaches the substrate under force control while the current decay rate before contact is accurately measured to set an environment-specific safe threshold. We detail the system setup, including probe fabrication and processing. The system's effectiveness is validated through multi-channel data recording. Furthermore, we observe pronounced differences in current-decay rates across various KCl solutions, highlighting the necessity of adaptive threshold calibration. This approach provides a universal strategy for achieving robust, high-quality SICM imaging across diverse environments.

Acoustic tweezers can achieve non-contact manipulation of particles and cells. Compared with other cell assembly techniques such as dielectrophoresis and surface patterning, acoustic tweezers have superior non-contact and biological safety properties, and do not require sample pre-treatment. They have great potential for application in the field of biomedicine. Moreover, holographic acoustic tweezers have greater spatial flexibility. However, problems such as the design and manufacturing of micrometer-scale acoustic tweezers and the characterization of high-frequency acoustic fields have hindered the development of holographic acoustic tweezers towards higher precision. In this study, a 50 MHz holographic ultrasonic tweezer was demonstrated using low-attenuation silicon lenses. The holographic lens was fabricated via deep silicon etching. Phase distributions were optimized using the iterative angular spectrum approach (IASA), with field reconstruction fidelity validated by finite element analysis (FEA). By integrating the lens with a 50 MHz LiNbO3 transducer, a two-point focusing ultrasonic field was achieved. The key point is that, in order to address the issue of the insufficiency of methods for characterizing and calibrating high-frequency acoustic fields, a force sensor based on micropipette was employed to locally calibrate the acoustic radiation force, revealing a linear dependence on excitation voltage. Finally, the device's biocompatibility and manipulation capability were demonstrated through two patterning modes of microspheres and yeast cells. The latter was found to be more difficult to capture acoustically than microsphere. This work represents one of the highest-frequency holographic tweezers reported to date, providing a robust platform for precise, programmable cell manipulation with calibrated force control.

Biomechanical features have emerged as innovative, label-free biomarkers that offer insights into physiological and pathological states. However, achieving reliable in situ biomechanical sensing in multiscale samples from single cells to whole organisms-remains a significant challenge due to the limitations of conventional methods in resolving soft, adhesive and large-scale samples. In this study, we present a nanoindenter derived from a closed-ended micropipette force sensor (MFS) that enables mapping of mechanical properties at different biological scales. The sensor’s design, characterized by a high aspect ratio and non-obstructive geometry, combining with a large range stage, facilitates the quantification for measuring the mechanical properties of soft and sticky samples. Our method was successful in characterizing the mechanical properties of tissue slices, organs, and even large-scale biological samples. Furthermore, our in-situ measurements on individual brains, leveraging the high aspect ratio of the sensor and a large working platform, allowed us to map the mechanical properties of a mouse brain after craniotomy. These results establish the system’s reliability in biomechanical characterization in multiscale, providing a robust platform for investigating mechanobiological processes and detecting pathological changes without the need for labeling.

Mechanical interactions among cells play an essential role in immune processes and tumorigenesis. However, quantitative mapping of the interactions between suspended cells remains challenging. In this study, an approach based on micropipette force sensors (MFS) has been developed for accurately manipulating cells and mapping intercellular interactions. The proposed method utilizes a holding probe to support the cells and an MFS probe for interaction force sensing; the intercellular interactions are quantified through force curve measurements in the approach-retraction process. To demonstrate the versatility of our technique, we measured the cell–substrate, cell–adherent, and cell-suspended interactions using mouse neuroblastoma N2a cells (Neuro2A). We demonstrated the potential of our method for measuring various cellular mechanical forces and revealed an increase in the stiffness of Neuro2A cells during mechanical measurements, which may be associated with cytoskeletal reinforcement in response to mechanical stimuli. The proposed technique has substantial implications for studying receptor-ligand effects on immune cells and intercellular adhesion. This advancement provides a method to enhance the comprehension of cellular mechanics and offers a tool for potential biomedical applications.

Accurately measuring both in-plane and out-of-plane mechanical properties is essential for understanding material behavior at the nanoscale. Conventional atomic force microscopy (AFM) techniques often struggle with the coupling between vertical and lateral forces, which can distort lateral mechanical property measurements. To address this limitation, we propose a novel Peak Force Torsional Resonance (PFTR) method that combines Peak Force Tapping for precise height control with torsional resonance for in-plane property extraction. This approach effectively decouples vertical and lateral forces, significantly reducing the influence of topography and vertical interactions on lateral measurements. Additionally, we introduce a mathematical model to accurately quantify lateral properties, such as shear modulus and lateral viscosity, independent of height variations. Experimental results confirm that the PFTR method achieves high-resolution imaging of both in-plane and out-of-plane mechanical properties, offering a more accurate and reliable solution for nanoscale mechanical characterization compared to conventional AFM-based methods. Note to Practitioners-This work addresses a common challenge in nanoscale mechanical property measurement: the interference from surface topography that affects accurate imaging of in-plane (lateral) properties. Traditional AFM methods struggle with this coupling effect, making it difficult to reliably measure both in-plane and out-of-plane mechanical characteristics-measurements that are vital in fields such as semiconductor manufacturing and materials development. This paper introduces PFTR Microscopy, a new AFM-based approach designed to decouple these forces and accurately resolve nanoscale mechanical properties. PFTR combines PFT for height control with torsional resonance to extract in-plane mechanical data without distortions from surface topography. By providing clear imaging of lateral properties and reducing topographical artifacts, PFTR enables more reliable assessments of materials such as semiconductor coatings, thin films, and composite compounds used in high-precision industries. PFTR is validated through experimental comparisons with conventional AFM methods, demonstrating that it achieves higher resolution and accuracy in in-plane measurements. While this approach provides robust data for characterizing homogeneous materials, further research is needed to adapt it for complex, heterogeneous surfaces and to simplify calibration for broader industrial application. The ability to distinguish mechanical properties at the nanoscale also suggests potential for applications in MEMS design, failure analysis, and the characterization of soft or biological materials.

Studying electrical and mechanical signals is crucial for understanding cellular behavior and underlying mechanisms. Among available measurement methods, micro‐ and nanopipette‐based techniques have emerged as promising tools for assessing both signals due to their biocompatibility, flexibility, versatility, and ease of integration. However, existing studies typically employ them for isolated tasks, either electrical recording or mechanical probing, lacking a unified framework to integrate multimodalities across contexts, restricting their combined potential. To overcome these limitations, this review focuses on recent advances in single‐cell signal measurement using micro‐ and nanopipettes and introduces the principles, operating modes, and key innovations of representative techniques. Furthermore, specific applications of micro‐ and nanopipettes are highlighted at molecular and cellular scales, including research on single ion channels, molecular interactions, biophysical and functional properties, and disease diagnosis and treatment. These applications have transformed the landscape of biological research, offering new insights into complex cellular processes. Finally, the related challenges regarding autonomous robotic measurement operation, highly reproducible data acquisition, and synchronized multidimensional signal recording are discussed, current preliminary solution strategies and future prospects are outlined. In conclusion, the pivotal role of micro‐ and nanopipettes in advancing biological research is highlighted, and further attention to their promising applications is encouraged.

Force curve is the most important techniques for accurate measuring the stiffness, adhesion and energy dissipation. However, due to the challenges of probe-cell localization, this type of single-cell analysis tool has become a labor-intensive and time-consuming procedure. Here, we demonstrate an automatic positioning methods based on micropipette for force curves acquisition. The automation covers the detection of cells in label-free images, pre-positioning and automatic focusing of micropipette, as well as automated force curves. This new method discards silicon-based probes used in traditional AFM, and instead utilizing a transparent micropipette with an unobstructed tip as the sensor. This advancement enables accurate localization of the probe tip and cell under an optical microscope. Furthermore, during the probe positioning process, we have implemented a pre-localization method using focused laser projection. This allows for manual adjustment of the probe tip within a range of 70 micrometers, providing precise region of interests (ROI) for automatic tip focusing. Combining with the aforementioned techniques. We also demonstrate the high-precision localization and force curve acquisition of eight fixed cells on a single image. The measurement results indicate that the positioning error will not exceed 3.4 mu m. Our work has effectively enhanced the efficiency of cellular mechanical measurements and holds the potential to achieve automated high-throughput single-cell analysis and drug screening.

As the demand for high-accuracy large-scale free-form devices in precision manufacturing fields such as aerospace, optics, and semiconductor manufacturing has increased, significant advances have been made in surface and topographic measurement techniques. These components have complex geometries and stringent accuracy requirements (sub-nanometer RMS for critical applications), posing significant challenges to existing metrology systems, especially in balancing large area coverage and ultra-high resolution. This paper reviews recent advances in full-frequency topographic measurement techniques for large free-form precision devices, focusing on both contact and non-contact measurement methods. Contact measurement techniques, such as coordinate measuring machines (CMMs), stylus profilers (SPs), and atomic force microscopes (AFMs), offer advantages in terms of high-resolution measurements, but have limitations in terms of measurement coverage and surface damage. In contrast, non-contact methods such as subaperture stitching (SSI), computational holography (CGH), optical profile scanners, fringe reflection (SCOTS) and partial compensation provide solutions for the measurement of large areas and sensitive materials, but have difficulties with environmental sensitivities and high-frequency roughness detection (>1000 mm−1). The paper concludes with a discussion of the future potential of hybrid systems integrating contact and non-contact methods that promise to overcome the limitations of current technologies and provide the next step in high-precision metrology over large areas in advanced manufacturing applications.

The accurate cross-scale measurement of surface profiles is essential in various fields, such as materials science and nanotechnology. Traditional measurement techniques, such as atomic force microscopy (AFM), provide high-resolution data but are limited in range, making it challenging to characterize surfaces with both fine and large-scale features comprehensively. This limitation creates a conflict in achieving precise, wide-range measurements necessary for advanced applications. To address this challenge, we propose a novel nested-feedback splicing measurement strategy that integrates AFM with an electrodynamic displacement system. This approach combines the high resolution of AFM with the extensive range capabilities of electrodynamic stages, allowing for detailed characterization across multiple scales. Our results demonstrate that the developed system significantly improves measurement accuracy, particularly in capturing detailed surface profiles over large areas. The experimental data validate the effectiveness of the proposed method, showing enhanced precision in multiscale topographic characterization and seamless integration between fine and large-scale measurements. This advancement paves the way for more comprehensive surface analyses in scientific research and industrial applications, highlighting the system's potential to revolutionize precision measurement technology.

Surface roughness significantly affects the functional performance of advanced materials, necessitating accurate nanoscale characterization via Atomic Force Microscopy (AFM). However, AFM’s high sampling requirements prolong measurement time and accelerate probe wear. To enhance efficiency, compressed sensing (CS) has been applied to improve AFM sampling strategies. Our literature review indicates that existing CS approaches primarily target high-quality image reconstruction, neglecting the accurate recovery of surface roughness information—a key objective in precision surface metrology. In this study, we propose a roughness-driven CS strategy to boost the efficiency and precision of AFM-based roughness measurements. We also theoretically demonstrate a nonlinear relationship between conventional CS evaluation metrics and surface roughness. Experimental results show that, compared to traditional image-based CS strategies, our method improves nanoscale roughness measurement accuracy by more than 80 %. This advancement not only reduces sampling requirements but also maintains high fidelity in roughness characterization, offering a robust tool for precise and efficient nanoscale analysis. Our approach supports performance-driven development of functional materials in fields such as microelectronics, optics, and nanomanufacturing.

Photothermal atomic force microscopy-infrared (AFM-IR) combines the nanoscale spatial resolution of AFM with the chemical identification capability of infrared spectroscopy and has thrived in various applications. Currently executed in three major AFM modes (contact, tapping, and peak force tapping) we introduce a fourth variant built upon force volume mode comprising a defined engage, hold, and retract segment in each pixel. IR laser pulsing at a probe resonance frequency during the constant-force hold segment duplicates the resonance-enhanced AFM-IR detection principle of contact mode. However, force volume AFM-IR removes the lateral forces that cause tip wear and sample damage while adding the spatial resolution of tapping AFM-IR. As demonstrated on different materials, this imaging and spectroscopy technique integrates monolayer sensitivity, sub-10 nm spatial chemical resolution, simultaneous nanomechanical property sensing, and precise force control. The ability to sweep the infrared laser repetition rate in each pixel provides additional, rich information in the form of contact resonance curves, while compensating for mechanically induced probe resonance shifts in an alternative to conventional phase-locked loop based frequency tracking. Such sweeps inherently consider the Q-factor (i.e., mechanical damping) in the AFM-IR response, a little investigated aspect. Furthermore, the probing depth can be varied by selecting different resonances recorded within a single broad frequency sweep. Switching to the surface sensitive AFM-IR detection scheme during the hold segment additionally limits the probing depth. These qualities should position force volume AFM-IR as a valuable addition to established AFM-IR modes.

The single beam acoustic tweezer (SBAT) is a powerful non-contant tool for pariticles manipulation. The SBAT manipulates particles by generating acoustic radiation force (ARF) when ultrasound acts upon them. However, the generation of ARF is often accompanied by acoustic streaming, which induces non-negligible hydrodynamic forces not only on the manipulated particles but also on the surrounding medium, potentially reducing the precision and controllability of the manipulation process. In this study, finite element simulations were employed to obtain the acoustic field generated by a focused lithium niobate transducer (100 MHz) and to further simulate the steady-state acoustic streaming field induced during particle manipulation. The simulation results enabled us to estimate the acoustic streaming fields generated by the 100 MHz SBAT under different micro sphere materials and substrate conditions. These results have important implications for selecting appropriate particles and substrate materials to enhance the precision of SBAT manipulation.

Cardiomyocytes (CMs) are the contractile motors of the heart that generate the force required to pump blood into the systemic circulations. Its contractive process can be described as electrical stimulation that ultimately leads force generation (excitation-contraction coupling). Investigation of the mechanical forces and electrical signals is crucial in heart disease research and related drug assessment. Despite the long-term development of instruments for measuring mechanical or electrical signals of CMs separately, in situ synchronous measurement of these signals of CMs still faces challenges. To address this gap, in this study, we developed cantilevered micropipette force electric sensor (CMFES) to realize mechanical and electrical signal measurements. We recorded, for the first time, the synchronous local beating, ion flow-related contraction characteristics, and action potential of CMs. The results revealed that during the late stage of Na+ influx in CMs, the cells began to contract, with a time difference of approximately 100-130 ms between the action potential and the contraction peak. Furthermore, to demonstrate the accuracy and capability of the proposed methods, we utilized CMFES to perform quantitative mechanical measurements, achieve high-resistance sealing, and record ion channel currents. In summary, our approach achieved measurement accuracy comparable to that of atomic force microscopy (AFM) and patch clamp techniques, which are currently considered the most precise technologies for mechanical and electrical measurements. We believe this novel approach has broad applications in various research areas involving the intersection of biomechanics and electrophysiology.

Large-sample atomic force microscopy (AFM) is crucial in semiconductor and optics manufacturing. However, significant mechanical vibration noise compromises imaging resolution. Owing to the absence of high-resolution noncontact vibration sensors, it is difficult to decouple mechanical vibration noise from topographic images. Here, we present an online vibration noise decoupling technique. The relative vibration between the AFM head and sample was measured using a squeeze film damping vibration sensor (SFDVS) and was then subtracted from the topographic images in real-time. Given the distinct frequency responses of the SFDVS and AFM to vibrations, the direct subtraction of the measured vibration from the AFM topography image would result in a significant decoupling error. To mitigate this problem, we designed a signal adjuster to correct the vibration sensor output and then obtained the optimal adjuster parameters by using the grid search method. The adjuster can effectively mitigate the disparity in the frequency responses of the SFDVS and the AFM, reducing the root mean square subtraction error from 0.98 to 0.32 nm, or by approximately -9.7 dB. Moreover, the efficiency of the proposed technique was demonstrated by imaging grating and silicon samples. The noise in the images was effectively reduced, thereby improving the accuracy of structure dimension and surface roughness measurements. The latency of the signal adjuster is about 20 mu s, enabling real-time noise decoupling. The results of this work are expected to resolve vibration issues not only in AFM but also in other sensitive measurement equipment.