SPIE Optics & Photonics 2026: Nanoscience and engineering plenaries

Metasurfaces, ultrathin arrays of subwavelength nanostructures, offer a fundamentally new route to shaping optical wavefronts, enabling compact and highly efficient flat optical systems. However, translating static metasurface functionality into fully programmable and electrically addressable meta-displays remains a central challenge.

Such organic meta-displays support real-time, user-driven holographic functionalities, illustrating how electrochemical material physics can be directly translated into system-level optical programmability. More broadly, this work points toward a future in which organic materials and meta-optics converge to enable compact, energy-efficient, and interactive flat photonic technologies.

Prof. Liu, who received her Ph.D. in Physics from the University of Stuttgart, Germany, has since worked as a postdoctoral fellow at the University of California, Berkeley, then as a Texas Instruments Visiting Professor at Rice University. In 2020, she returned to Stuttgart, where she became the Director of the 2nd Physics Institute.

Further information from Q&A

Following Prof. Liu’s presentation, the Q and A session revealed further technical details and the potential of her group’s emergent display technology. She was asked how much power would be required to switch the pixels on and off; was there any limiting thermal effect; and what was the switching time.

Prof Liu said, “I have made a comparison between liquid crystal-based meta services and the active polymer-based meta surfaces. A benefit of the active polymer-based meta surfaces is their lower power consumption. It is more energy-friendly in the active polymer case. Thermal effects are not a significant concern at this point.”

She added, “Currently, the switching time is of the order of a millisecond. In the future, if we need to do it faster, there are a lot of things we still need to improve. In fact, for the active polymers, one can achieve a switching time in the order of microseconds. But this requires a lot of polymer synthesis optimization. So, right now, we are still using a preliminary connecting polymer growth approach, which is not fully optimized.”So what is the potential of the new display technology?

Prof. Liu answered: “At this stage, we cannot replace conventional display technologies. We are still at the stage or proof of concept. There are a lot of technical challenges that we need to face.For example, right now, we are still facing a difficulty to expand the number of pixels. I can today show you 8 by 8-pixel models. But for larger areas of displays I will need to achieve displays of at least several thousand pixels. To achieve that I will need to be able to control the routing of electrons to control the individual pixels. Where we are now is a bottleneck so the current conclusion is that we are still at the fundamental research stage.” 

From single-molecule detection to living plant diagnostics

Second plenary presenter Prof. Michael Strano is currently the Carbon P. Dubbs Professor in the Chemical Engineering Department at Massachusetts Institute of Technology (MIT).  His research focuses on biomolecule-nanoparticle interactions and the surface chemistry of low dimensional systems, nano-electronics, and applications of vibrational spectroscopy to nanotech. 

The plenary presentation was entitled “Exciton-driven optics and molecular recognition in carbon nanotube nanosensors”. In it, Prof. Strano outlined that “fluorescent single-walled carbon nanotubes (SWCNTs) have emerged as uniquely powerful optical probes for biosensing owing to their stable near-infrared emission, excitonic sensitivity to local perturbations, and compatibility with scattering biological media. This plenary will highlight how nanoscale optical phenomena—specifically one-dimensional exciton transport and quenching—enable single-molecule detection.” 

By engineering the corona phase surrounding SWCNTs, including DNA, polymers, and aptamer-functionalized coatings, molecular recognition can be programmed without perturbing the nanotube’s intrinsic photophysics. These corona phase molecular recognition (CoPhMoRe) strategies produce highly selective and reversible optical responses to analytes ranging from nitric oxide and hydrogen peroxide to proteins and neurotransmitters.

He said, “These optical nanosensors extract quantitative molecular dynamics from fluorescence trajectories, enabling real-time, label-free measurements of single-molecule adsorption, desorption, and cellular efflux processes.”

Prof. Strano also described advances in optical instrumentation and signal processing, including wavelength-induced frequency filtering (WIFF), which enhances signal-to-noise ratios in highly scattering environments and extends nanosensor imaging to centimeter-scale tissue depths. “These developments have enabled unprecedented applications in living systems, from mapping reactive oxygen species signaling at single-cell resolution to detecting protein secretion from individual microorganisms in real time,” he said. 

Applications including real-time imaging of wound-induced hydrogen peroxide waves, multiplexed detection of stress signaling molecules, and direct measurement of plant hormones such as auxin illustrate a new paradigm for precision agriculture. 

He concluded, “By enabling continuous, spatially resolved biochemical monitoring in crops, these optical nanosensor platforms open pathways toward early stress diagnostics, climate-resilient agriculture, and next-generation biointegrated sensing technologies.”