Nanowerk May 11, 2023 Researchers in the Netherlands recreated the unique human ability of extensive perspiration and controlled friction in self-assembled cholesteric liquid crystals, mimicking the natural processes that occur in the dermis and epidermis of human skin. It was achieved by inducing porosity in responsive, liquid-bearing material through the controlled-polymerization phase-separation process. The unique topography of human fingerprints was further emulated in the materials by balancing the parallel chirality-induced force and the perpendicular substrate-anchoring force during synthesis. As a result, artificial fingertips were capable of secreting and re-absorbing liquid upon light illumination. By demonstrating the function of the soft […]
Tag Archives: S&T the Netherlands
Researchers develop ultraefficient white light laser on a chip
Phys.org March 13, 2023 Supercontinuum lasers are able to produce a continuous spectrum of color and can therefore appear white. To generate the wide bandwidth of colors, supercontinuum lasers have a high peak power consumption, they are enormous and have to be stabilized in a laboratory. Researchers in the Netherlands have developed a scheme where the input energy requirements for integrated supercontinuum generation are drastically lowered by orders of magnitude for bandwidth generation of the order of 500–1000 nm. They achieved an efficiency enhancement by factors reaching 2800 through sign-alternating dispersion in a CMOS-compatible silicon nitride waveguide. They showed that the […]
Electron pairing in quantum dots as a new approach to qubit research
Phys.org November 25, 2022 Materials with intrinsic p-wave superconductivity, hosting Cooper pairs made of equal-spin electrons, have not been conclusively identified, nor synthesized, despite promising progress. Instead, engineered platforms where s-wave superconductors are brought into contact with magnetic materials have shown convincing signatures of equal-spin pairing. Researchers in the Netherlands have directly measured equal-spin pairing between spin-polarized quantum dots. The pairing is proximity-induced from an s-wave superconductor into a semiconducting nanowire with strong spin–orbit interaction. They demonstrated such pairing by showing that breaking a Cooper pair can result in two electrons with equal spin polarization. Their results demonstrated controllable detection […]
Using machine learning to infer rules for designing complex mechanical metamaterials
Phys.org November 23, 2022 Combinatorial problems arising in puzzles, origami, and (meta) material design have rare sets of solutions, which define complex and sharply delineated boundaries in configuration space. The boundaries are difficult to capture with conventional statistical and numerical methods. Researchers in the Netherlands have shown that convolutional neural networks can learn to recognize these boundaries for combinatorial mechanical metamaterials, down to the finest detail, despite using heavily undersampled training sets, and can successfully generalize. According to the researchers even if machine learning is typically a “black box” approach, it can still be very valuable for exploring the design […]
‘SuperGPS’ Technology Accurately Pinpoints Your Position Within Inches
Science Alert November 23, 2022 Although GNSS can provide centimetre-level precision, GNSS receivers are prone to many-metre errors owing to multipath propagation and an obstructed view of the sky, which occur particularly in urban areas where accurate positioning is most needed. Moreover, the vulnerabilities of GNSS, combined with the lack of a back-up system, pose a severe risk to GNSS-dependent technologies. Researhers in the Netherlands have demonstrated a terrestrial positioning system that is independent of GNSS and offers superior performance through a constellation of radio transmitters, connected and time-synchronized at the subnanosecond level through a fibre-optic Ethernet network. Using optical […]
A navigation system with 10 centimeter accuracy
Science Daily November 16, 2022 The vulnerabilities of Global navigation satellite systems (GNSS) combined with the lack of a back-up system pose a severe risk to GNSS-dependent technologies. Researchers in the Netherlands used optical and wireless transmission schemes similar to those encountered in mobile communication networks, and exploiting spectrally efficient virtual wideband signals. The detrimental effects of multipath propagation were mitigated, thus enabling robust decimetre-level positioning and subnanosecond timing in a multipath-prone outdoor environment. They demonstrated that their system is independent of GNSS and offers superior performance through a constellation of radio transmitters, connected and time-synchronized at the subnanosecond level […]
Controlling non-classical mechanical states in a phononic waveguide architecture
Phys.org June 24, 2022 Researchers in the Netherlands used a cavity–waveguide architecture, where the cavity is used as a source and detector for the mechanical excitations while the waveguide has a free-standing end to reflect the phonons. This enabled them to observe multiple round trips of phonons between the source and the reflector. The long mechanical lifetime of almost 100 μs demonstrated the possibility of nearly lossless transmission of single phonons over tens of centimetres. Their experiment demonstrated full on-chip control over travelling single phonons strongly confined in the direction transverse to the propagation axis, potentially enabling a time-encoded multimode quantum […]
Physicists build an atom laser that can stay on forever
Phys.org June 14, 2022 Bose–Einstein condensates (BECs) are important to quantum simulation and sensing. A long-standing constraint for quantum gas devices has been the need to execute cooling stages time-sequentially, restricting these devices to pulsed operation. Researchers in the Netherlands demonstrated continuous Bose–Einstein condensation by creating a continuous-wave (CW) condensate of strontium atoms that lasts indefinitely. The coherent matter wave is sustained by amplification through Bose-stimulated gain of atoms from a thermal bath. By steadily replenishing this bath while achieving 1,000 times higher phase-space densities than previous works they maintained the conditions for condensation. Their experiment is the matter wave […]
A new method for quantum computing
Phys.org January 31, 2022 Using trapped-ion platform and optical tweezers researchers in the Netherlands have constructed new building blocks for quantum computing that pose fewer technical difficulties than current state-of-the art methods. Since the electric field allows for long-range qubit-qubit interactions mediated by the center-of-mass motion of the ion crystal alone, it is inherently scalable to large ion crystals. The proposed scheme does not rely on ground-state cooling. They studied the effects of imperfect cooling of the ion crystal, as well as the role of unwanted qubit-motion entanglement, and discuss the prospects of implementing the state-dependent tweezers in the laboratory… […]
New tiny sensor makes the invisible visible
Phys.org January 12, 2022 Researchers in the Netherlands developed and demonstrated a different approach to spectral sensing which dramatically simplifies the requirements on the hardware and allows the monolithic integration of the sensors. They used an array of resonant-cavity-enhanced photodetectors, each featuring a distinct spectral response in the 850-1700 nm wavelength range. They showed that prediction models can be built directly using the responses of the photodetectors, despite the presence of multiple broad peaks, releasing the need for spectral reconstruction. They used the sensor to measure the nutritional properties of many materials including milk and to classify different types of plastic. […]