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G.J. Verbiest

29 records found

Resonators based on two-dimensional (2D) materials have exceptional properties for application as nanomechanical sensors, which allows them to operate at high frequencies with high sensitivity. However, their performance as nanomechanical sensors is currently limited by their low ...
Heat transport in two dimensions is fundamentally different from that in three dimensions. As a consequence, the thermal properties of 2D materials are of great interest, from both scientific and application points of view. However, few techniques are available for the accurate d ...
The high susceptibility of ultrathin two-dimensional (2D) material resonators to force and temperature makes them ideal systems for sensing applications and exploring thermomechanical coupling. Although the dynamics of these systems at high stress has been thoroughly investigated ...
Acoustic levitation is an attractive and versatile technique that offers several advantages in terms of particle size, range, reconfigurability, and ease of use with respect to alternative levitating techniques. In this paper, we study the use of active damping to improve the res ...
Suspended drums made of 2D materials hold potential for sensing applications. However, the industrialization of these applications is hindered by significant device-to-device variations presumably caused by non-uniform stress distributions induced by the fabrication process. Here ...
Most microphones detect sound-pressure-induced motion of a membrane. In contrast, we introduce a microphone that operates by monitoring sound-pressure-induced modulation of the air compressibility. By driving a graphene membrane at resonance, the gas, that is trapped in a squeeze ...
Microphones exploit the motion of suspended membranes to detect sound waves. Since the microphone performance can be improved by reducing the thickness and mass of its sensing membrane, graphene-based microphones are expected to outperform state-of-the-art microelectromechanical ...

Sensors in agriculture

Towards an Internet of Plants

To ensure a sustainable future and combat food scarcity, we must boost agricultural productivity, improve climate resilience and optimize resource usage. There is untapped potential for dense wireless sensor networks in agriculture that can increase yields and support resilient p ...
A low-cost glass-based microfluidic flow cell with a piezo actuator is built using off-the-shelf parts (total cost €9 per device) to apply acoustophoretic force on polystyrene micro-beads. The main challenge in the fabrication of these devices was to ensure their leak tightness, ...
To better understand the interactions between biological molecules, a high optical resolution in all three dimensions is crucial. The intrinsically lower axial resolution of microscopes however, is a limiting factor in fluorescence imaging, correspondingly in fluorescence based s ...
We propose to use the State Estimation by Sum-of-Norms Regularisation (STATESON-)algorithm for recovering the tip-sample interaction in high-speed tapping mode atomic force microscopy (AFM). This approach enables accurate sample height estimation for each independent cantilever o ...
The resonance frequency of ultra-thin layered nanomaterials changes nonlinearly with the tension induced by the pressure from the surrounding gas. Although the dynamics of pressurized nanomaterial membranes have been extensively explored, recent experimental observations show sig ...
Heat transport by acoustic phonons in two-dimensional (2D) materials is fundamentally different from that in 3D crystals because the out-of-plane phonons propagate in a unique way that strongly depends on tension and bending rigidity. Here, using optomechanical techniques, we exp ...
Atomic layer deposition (ALD), a layer-by-layer controlled method to synthesize ultrathin materials, provides various merits over other techniques such as precise thickness control, large area scalability and excellent conformality. Here we demonstrate the possibility of using AL ...
Fluid flow processes such as drainage and evaporation in porous media are crucial in geological and biological systems. The motion of the displacement front of a moving fluid through multi-phase interfaces is often associated with abrupt mechanical energy release, detectable as a ...
Conoscopic interferometry is a promising detection technique for ultrafast acoustics. By focusing a probe beam through a birefringent crystal before passing it through a polarizer, conoscopic interferences sculpt the spatial profile of the beam. The use of these patterns for acou ...
Suspended piezoelectric thin films are key elements enabling high-frequency filtering in telecommunication devices. To meet the requirements of next-generation electronics, it is essential to reduce device thickness for reaching higher resonance frequencies. Here, the high-qualit ...
Although it is well known that plants emit acoustic pulses under drought stress, the exact origin of the waveform of these ultrasound pulses has remained elusive. Here, we present evidence for a correlation between the characteristics of the waveform of these pulses and the dimen ...
Although 2D materials hold great potential for next-generation pressure sensors, recent studies revealed that gases permeate along the membrane-surface interface, necessitating additional sealing procedures. In this work, we demonstrate the use of free-standing complex oxides as ...
We report on the effect of Fabry-Pérot (FP) resonance on hot-carrier electroluminescence (EL) spectra and the optical power efficiencies of silicon (Si) avalanche-mode (AM) LEDs in the wavelength range from 500 nm to 950 nm. The LEDs, fabricated in a silicon-on-insulator photonic ...