Breaking Voltage Limits: Measuring Over 400 V with Dual Harmonic KPFM

At the IEEE ISAF-ICE-ISIF-PFM 2025 conference, held July 13–18, 2025, in Graz, Austria, Dr. Qiancheng Zhang presented a breakthrough in high surface potential measurement — Dual Harmonic Kelvin Probe Force Microscopy (DH-KPFM) now capable of measuring surface potentials exceeding 400 volts.

Traditional KPFM techniques, while powerful, typically max out at 10 V and rely on a feedback loop. Dr. Zhang’s work pushes these boundaries by using DH-KPFM—an open-loop, AC-only method that eliminates the need for DC bias and enables measurements in liquid environments or on DC-sensitive materials.

The stiffer cantilevers dramatically increase the max measurable voltage range, with a 247 N/m cantilever successfully detecting up to 432.9 V. This high-voltage capability was further applied to measure pyroelectric coefficients of materials like lithium niobate and TGS.

This advancement opens new doors for nanoscale measurements in high-field materials and extreme conditions. We're now seeking collaborations where high-voltage, liquid-phase, or DC-sensitive surface potential measurements are needed.

Dr. Qiancheng Zhang Presented LPFM Study of Collagen at MBI 2025

On May 14, 2025, Dr. Qiancheng Zhang gave an oral presentation at the Matrix Biology Ireland 2025 conference at University College Dublin. His talk focused on using Lateral Piezoresponse Force Microscopy (LPFM) to study collagen as a prototypical piezoelectric biomaterial for biomedical applications.

He introduced the working principle of LPFM and its ability to detect shear piezoelectric signals from individual collagen fibrils. He presented results from various tissues, including fish scale, rat tail tendon, dentin, cornea, and collagen membranes. He talked about LPFM measurements of human skin cross-sections, revealing depth-dependent variations in collagen organization and quantitative piezoresponse within the dermis.

Claudia Sosa Espada’s Summer Internship

We were delighted to welcome Claudia Sosa Espada, an undergraduate student from University College Dublin (UCD), who joined us a few weeks back as a summer intern.Claudia has been actively involved in research during her time here, and recently, she presented her internship findings in a very well-received talk. Her work focused on the ferroelectric properties of Hafnia films, a promising material in the field of electronics.

She explored the influence of humidity and measurement conditions on the ferroelectric response, and also looked into understanding and reducing the imprint effect in these films, an important aspect for improving device performance.Her presentation was insightful and clearly showed her enthusiasm and hard work over the last few weeks.

A big thanks to UCD, especially the School of Physics, for supporting such young researchers and for organizing the presentation session. The coffee and donuts were a lovely touch and much appreciated by everyone!

We wish Claudia all the best in her future academic journey and look forward to more collaborations with students like her!

Dr. Qiancheng Zhang delivered an oral presentation at PDSTM2025 in Dublin

Our group had the pleasure of contributing to the 9th International Conference on Phase Transition and Dynamical Properties of Spin Transition Materials (PDSTM2025), hosted at University College Dublin from May 25–29, 2025. This biennial event organized by UCD collaborator Prof Grace Morgan brought together leading scientists from around the world to share breakthroughs in spin crossover (SCO) materials, phase transitions, and multifunctional molecular systems.

Dr. Qiancheng Zhang delivered an oral presentation titled: “Integrating Spin Crossover and Ferroelectricity in Dual Switchable Transition Metal Complexes for Enhanced Data Storage”

In his talk, Qiancheng introduced the principle of piezoresponse force microscopy (PFM), presented measurements of piezoelectricity and pyroelectricity, and explored switchable behavior in two types of Fe(III) complexes.

We thank the conference organizers for a vibrant program and the opportunity to connect with fellow researchers in the field. We look forward to advancing this research and sharing further updates soon.

The work was supported by Research Ireland (Science Foundation Ireland and Irish Research Council).

Lima Passed his Stage Transfer Assessment!

Special Blog Post by Yevhen Brych

On the eve of Valentine’s day Lima was officially promoted from phd candidate to phd student. At his stage transfer presentation Lima outlined his project goal to switch ferroelectric materials in liquid. Lima first introduced the material class of ferroelectrics, pitching them as a competitor to silicon based technologies. He explained that ferroelectric materials are built up from smaller domains which are broadly known for being polarisable with an electric field. Lima also discussed other exotic ways to pole domains such as with light and mechanical strain. This inspired him to pursue electrochemical switching in liquid. Lima stated that this was a necessity because ferroelectric behaviour is heavily influenced by atmospheric conditions. Liquids provide a controlled environment, a way to standardize these measurements. Lima also argued that liquid switching of ferroelectric materials would increase device applications and reliability.

Lima then presented some preliminary piezo force microscopy results on barium titanate samples. He showed that the phase of the domains (orientation of poles) can be switched with mechanical force. One of the challenges with liquid switching is identifying a suitable ionic solution as well as a module to submerge the sample during the measurement. However he assured the audience that a custom liquid cell for his measurements is in the works.

Overall Lima was able to convince the stage transfer panel about the feasibility of this measurement with detailed objectives. As well as a plan to overcome the challenges with liquid switching of ferroelectric materials.


Una Europa Symposium on Future Materials & Technologies

From January 22–25, 2025, members of our lab took part in Una Europa StartScience and the Symposium on Future Materials & Technologies at the historic Jagiellonian University in Kraków, Poland (founded in 1364!). It was a fantastic opportunity to connect with researchers from both academia and industry.

Drs. Waseem Wani and Qiancheng Zhang delivered excellent oral and poster presentations, with Waseem winning a Poster Prize for his work on nanoelectromechanical characterization of hafnia thin films.

A huge thank you to the organizers in Kraków for putting together such an inspiring event—we’re excited for future collaborations within the Una Europa community!


Group Updates

There have been many changes - great successes and new faces! Sawsan (PhD and postdoc) took a position with Intel Ireland. Hossam and Emrullah graduated with their PhD and now work for Nikon and Abbott Laboratories, respectively. Fengyuan took a postdoc position with Prof. Jiangyu Li. Longtime group member Jason joined Coca Cola as a data scientist. Srikanth went to TCD for a postdoc and then to Analog Devices on an SFI Industry RD&I Fellowship. Two year CSC PhD student Qiancheng graduated and returned as a postdoc. Alyona joined as a co-supervised PhD student and recently secured an IRC fellowship. Bahar joined as a researcher and secured a position at TCD (and had a baby - congratulations!). Visiting PhD student Xabi joined for 4 months and just became a father - congratulations! The lab is full with external users and summer students - great to have Sam, Surabhi, Ella, Leena, Caiden, and Gustavo in the lab - happy days! New group members will be joining soon!