@article{21982,
  abstract     = {A floating Leidenfrost droplet exhibits curvature inversion of its underside, due to the balance of vapor pressure and surface tension. Using interferometric imaging, we find different behavior for a levitated hydrogel sphere. Curvature inversion is observed briefly just after deposition, but quickly gives way to a steady state with no inversion. We show the essential role of vaporization in shaping the underbelly of the hydrogel, where changes due to direct mass loss are more significant than the balance of vapor pressure and elastic forces.},
  author       = {Diaz Melian, Vicente L and Lenton, Isaac C and Binysh, Jack and Souslov, Anton and Waitukaitis, Scott R},
  issn         = {2470-0053},
  journal      = {Physical Review E},
  number       = {5},
  publisher    = {American Physical Society},
  title        = {{Geometry of the vapor layer under a Leidenfrost hydrogel sphere}},
  doi          = {10.1103/m7gr-2t6j},
  volume       = {113},
  year         = {2026},
}

@article{21370,
  abstract     = {Through digital imaging, microscopy has evolved from primarily being a means for visual observation of life at the micro- and nano-scale, to a quantitative tool with ever-increasing resolution and throughput. Artificial intelligence, deep neural networks, and machine learning (ML) are all niche terms describing computational methods that have gained a pivotal role in microscopy-based research over the past decade. This Roadmap encompasses key aspects of how ML is applied to microscopy image data, with the aim of gaining scientific knowledge by improved image quality, automated detection, segmentation, classification and tracking of objects, and efficient merging of information from multiple imaging modalities. We aim to give the reader an overview of the key developments and an understanding of possibilities and limitations of ML for microscopy. It will be of interest to a wide cross-disciplinary audience in the physical sciences and life sciences.},
  author       = {Volpe, Giovanni and Wählby, Carolina and Tian, Lei and Hecht, Michael and Yakimovich, Artur and Monakhova, Kristina and Waller, Laura and Sbalzarini, Ivo F. and Metzler, Christopher A. and Xie, Mingyang and Zhang, Kevin and Lenton, Isaac C and Rubinsztein-Dunlop, Halina and Brunner, Daniel and Bai, Bijie and Ozcan, Aydogan and Midtvedt, Daniel and Wang, Hao and Li, Tongyu and Sladoje, Nataša and Lindblad, Joakim and Smith, Jason T. and Ochoa, Marien and Barroso, Margarida and Intes, Xavier and Qiu, Tong and Yu, Li Yu and You, Sixian and Liu, Yongtao and Ziatdinov, Maxim A. and Kalinin, Sergei V. and Sheridan, Arlo and Manor, Uri and Nehme, Elias and Goldenberg, Ofri and Shechtman, Yoav and Moberg, Henrik K. and Langhammer, Christoph and Špačková, Barbora and Helgadottir, Saga and Midtvedt, Benjamin and Argun, Aykut and Thalheim, Tobias and Cichos, Frank and Bo, Stefano and Hubatsch, Lars and Pineda, Jesus and Manzo, Carlo and Bachimanchi, Harshith and Selander, Erik and Homs-Corbera, Antoni and Fränzl, Martin and De Haan, Kevin and Rivenson, Yair and Korczak, Zofia and Adiels, Caroline Beck and Mijalkov, Mite and Veréb, Dániel and Chang, Yu Wei and Pereira, Joana B. and Matuszewski, Damian and Kylberg, Gustaf and Sintorn, Ida Maria and Caicedo, Juan C. and Cimini, Beth A. and Lediju Bell, Muyinatu A. and Saraiva, Bruno M. and Jacquemet, Guillaume and Henriques, Ricardo and Ouyang, Wei and Le, Trang and Gómez-De-Mariscal, Estibaliz and Sage, Daniel and Muñoz-Barrutia, Arrate and Lindqvist, Ebba Josefson and Bergman, Johanna},
  issn         = {2515-7647},
  journal      = {Journal of Physics: Photonics},
  number       = {1},
  publisher    = {IOP Publishing},
  title        = {{Roadmap on deep learning for microscopy}},
  doi          = {10.1088/2515-7647/ae0fd1},
  volume       = {8},
  year         = {2026},
}

@article{20847,
  abstract     = {We report on an experimental active matter system with motion restricted to four cardinal directions. Our particles are magnetite-doped colloidal spheres driven by the Quincke electrorotational instability. The absence of a magnetic field (|𝑩|=0) leads to circular trajectories interspersed with short spontaneous runs. Intermediate fields (|𝑩|≲20mT) linearize the motion along the axis perpendicular to 𝑩. At high magnetic fields, we observe the surprising emergence of a second, distinct linearization along the axis parallel to 𝑩. With numerical simulations, we show that this behavior can be explained by anisotropic magnetic susceptibility.},
  author       = {Fitzgerald, Eavan and Clavaud, Cécile and Das, Debasish and Lenton, Isaac C and Waitukaitis, Scott R},
  issn         = {2470-0053},
  journal      = {Physical Review E},
  number       = {6},
  publisher    = {American Physical Society},
  title        = {{Rolling at right angles: Magnetic anisotropy enables dual-anisotropic active matter}},
  doi          = {10.1103/1ss8-31rb},
  volume       = {112},
  year         = {2025},
}

@article{20295,
  abstract     = {Scanning Kelvin probe microscopy (SKPM) is a powerful technique for macroscopic imaging of the electrostatic potential above a surface. Though most often used to image work-function variations of conductive surfaces, it can also be used to probe the surface charge on insulating surfaces. In both cases, relating the measured potential to the underlying signal is non-trivial. Here, general relationships are derived between the measured SKPM voltage and the underlying source, revealing either can be cast as a convolution with an appropriately scaled point spread function (PSF). For charge that exists on a thin insulating layer above a conductor, the PSF has the same shape as what would occur from a work-function variation alone, differing by a simple scaling factor. This relationship is confirmed by: (1) backing it out from finite-element simulations of work-function and charge signals, and (2) experimentally comparing the measured PSF from a small work-function target to that from a small charge spot. This scaling factor is further validated by comparing SKPM charge measurements with Faraday cup measurements for highly charged samples from contact-charging experiments. These results highlight a heretofore unappreciated connection between SKPM voltage and charge signals, offering a rigorous recipe to extract either from experimental data.},
  author       = {Lenton, Isaac C and Pertl, Felix and Shafeek, Lubuna B and Waitukaitis, Scott R},
  issn         = {2196-7350},
  journal      = {Advanced Materials Interfaces},
  number       = {19},
  publisher    = {Wiley},
  title        = {{A duality between surface charge and work function in scanning Kelvin probe microscopy}},
  doi          = {10.1002/admi.202500521},
  volume       = {12},
  year         = {2025},
}

@article{20705,
  abstract     = {Optical tweezers are widely used as a highly sensitive tool to measure forces on micron-scale particles. One such application is the measurement of the electric charge of a particle, which can be done with high precision in liquids, air, or vacuum. We experimentally investigate how the trapping laser itself can electrically charge such a particle, in our case a ∼1  μ⁢m SiO2 sphere in air. We model the charging mechanism as a two-photon process which reproduces the experimental data with high fidelity.},
  author       = {Stöllner, Andrea and Lenton, Isaac C and Volosniev, Artem and Millen, James and Shibuya, Renjiro and Ishii, Hisao and Rak, Dmytro and Alpichshev, Zhanybek and David, Grégory and Signorell, Ruth and Muller, Caroline J and Waitukaitis, Scott R},
  issn         = {1079-7114},
  journal      = {Physical Review Letters},
  number       = {21},
  publisher    = {American Physical Society},
  title        = {{Using optical tweezers to simultaneously trap, charge, and measure the charge of a microparticle in air}},
  doi          = {10.1103/5xd9-4tjj},
  volume       = {135},
  year         = {2025},
}

@article{20481,
  abstract     = {Kelvin probe force microscopy (KPFM) is widely used in stationary and dynamic studies of contact electrification. An obvious question that connects these two has been overlooked: when are charge dynamics too fast for stationary studies to be meaningful? Using a rapid transfer system to quickly perform KPFM after contact, we find the dynamics are too fast in all but the best insulators. Our data further suggest that dynamics are caused by bulk as opposed to surface conductivity, and that charge-transfer heterogeneity is less prevalent than previously suggested.},
  author       = {Pertl, Felix and Lenton, Isaac C and Cramer, Tobias and Waitukaitis, Scott R},
  issn         = {1079-7114},
  journal      = {Physical Review Letters},
  number       = {14},
  publisher    = {American Physical Society},
  title        = {{No time for surface charge: How bulk conductivity hides charge patterns from Kelvin probe force microscopy in contact-electrified surfaces}},
  doi          = {10.1103/lcsm-xxty},
  volume       = {135},
  year         = {2025},
}

@article{17373,
  abstract     = {Scanning Kelvin probe microscopy (SKPM) is a powerful technique for investigating the electrostatic properties of material surfaces, enabling the imaging of variations in work function, topology, surface charge density, or combinations thereof. Regardless of the underlying signal source, SKPM results in a voltage image, which is spatially distorted due to the finite size of the probe, long-range electrostatic interactions, mechanical and electrical noise, and the finite response time of the electronics. In order to recover the underlying signal, it is necessary to deconvolve the measurement with an appropriate point spread function (PSF) that accounts the aforementioned distortions, but determining this PSF is difficult. Here, we describe how such PSFs can be determined experimentally and show how they can be used to recover the underlying information of interest. We first consider the physical principles that enable SKPM and discuss how these affect the system PSF. We then show how one can experimentally measure PSFs by looking at well-defined features, and that these compare well to simulated PSFs, provided scans are performed extremely slowly and carefully. Next, we work at realistic scan speeds and show that the idealized PSFs fail to capture temporal distortions in the scan direction. While simulating PSFs for these situations would be quite challenging, we show that measuring PSFs with similar scan conditions works well. Our approach clarifies the basic principles and inherent challenges to SKPM measurements and gives practical methods to improve results.},
  author       = {Lenton, Isaac C and Pertl, Felix and Shafeek, Lubuna B and Waitukaitis, Scott R},
  issn         = {1089-7550},
  journal      = {Journal of Applied Physics},
  number       = {4},
  publisher    = {AIP Publishing},
  title        = {{Beyond the blur: Using experimentally determined point spread functions to improve scanning Kelvin probe imaging}},
  doi          = {10.1063/5.0215151},
  volume       = {136},
  year         = {2024},
}

@inproceedings{14864,
  author       = {Stöllner, Andrea and Lenton, Isaac C and Muller, Caroline J and Waitukaitis, Scott R},
  booktitle    = {EGU General Assembly 2023},
  location     = {Vienna, Austria & Virtual},
  publisher    = {European Geosciences Union},
  title        = {{Measuring spontaneous charging of single aerosol particles}},
  doi          = {10.5194/egusphere-egu23-6166},
  year         = {2023},
}