A*STAR-IMRE 2D Magnetic Sensors Breakthrough: Overcoming Sensitivity-Speed Trade-off in Advanced Sensing Technology

In the rapidly evolving landscape of advanced sensing technology, the A*STAR-IMRE 2D magnetic sensors breakthrough stands out as a game-changer for Singapore's research ecosystem. Traditional magnetic field sensors have long grappled with a fundamental limitation: the sensitivity-speed trade-off. High sensitivity, essential for detecting minute magnetic fields in applications like medical imaging and electric vehicles, often comes at the expense of slow response times. Conversely, fast sensors sacrifice precision. Researchers at the Institute of Materials Research and Engineering (IMRE), under the Agency for Science, Technology and Research (A*STAR), have shattered this barrier using innovative two-dimensional (2D) van der Waals (vdW) materials, enabling sensors that deliver both ultra-high sensitivity and lightning-fast speeds.

This development not only propels Singapore's position as a global hub for materials science but also opens doors for higher education institutions like the National University of Singapore (NUS) and Nanyang Technological University (NTU), which frequently collaborate with IMRE on cutting-edge projects. By integrating 2D layered ferromagnets, these sensors achieve unprecedented performance, promising transformative impacts across industries.

Magnetic sensors detect variations in magnetic fields by converting them into electrical signals. Sensitivity refers to the smallest detectable field change, measured in nanotesla (nT), while speed is the response time, often in microseconds (μs). Conventional Hall effect or giant magnetoresistance (GMR) sensors excel in one area but falter in the other. For instance, thick ferromagnetic layers boost sensitivity but slow electron dynamics due to domain wall pinning, while thin films offer speed but reduced signal amplitude.

In Singapore's humid, high-precision manufacturing environment, where consumer electronics and biomedical devices dominate, this trade-off hinders progress. IMRE's solution leverages atomically thin 2D vdW magnets, such as chromium triiodide (CrI3) or iron germanium telluride (Fe3GeTe2), where interlayer coupling can be tuned without bulky substrates.

The image above captures IMRE scientists at work on wafer-scale 2D materials, a cornerstone of their sensor innovation.

IMRE's breakthrough involves stacking 2D ferromagnetic layers with precise vdW forces, creating heterostructures that amplify spin-orbit torque while minimizing damping. The process unfolds step-by-step:

• Step 1: Wafer-Scale Synthesis - Using chemical vapor deposition (CVD), IMRE grows electronic-grade transition metal dichalcogenides (TMDCs) like MoS2 as substrates, ensuring uniformity over 8-inch wafers.
• Step 2: Ferromagnetic Layer Deposition - Atomic layer deposition (ALD) of CrI3 or VSe2 monolayers, with thickness controlled to 1-5 layers for optimal Curie temperature above room temperature (300K).
• Step 3: Heterostructure Assembly - Transfer printing aligns layers, twisting angles to induce moiré patterns that enhance magnetic anisotropy.
• Step 4: Device Fabrication - Patterning into Hall bars or anomalous Hall effect (AHE) devices, encapsulated in hexagonal boron nitride (hBN) for stability.
• Step 5: Characterization - Cryogenic magnetometry reveals sensitivity of 10 nT/√Hz at 1 MHz bandwidth, 100x faster than silicon-based sensors.

This yields a response time under 1 μs with sensitivity rivaling SQUIDs (superconducting quantum interference devices), but operable at ambient conditions.

IMRE's prototypes demonstrate a magnetic sensitivity of 5 nT/√Hz at 10 kHz, with bandwidth up to 100 MHz—overcoming the trade-off via low Gilbert damping (α < 0.01). Compared to commercial AMR sensors (100 nT/√Hz, 1 kHz), this is a leap forward. Real-world tests in Singapore's humid labs confirmed stability over 10,000 cycles, with power consumption below 1 mW.

Such metrics position Singapore at the forefront, aligning with the Smart Nation initiative.

In electric vehicles (EVs), these sensors enable precise motor control, reducing energy loss by 15%—critical for Singapore's EV push. In biomedicine, non-invasive neural magnetic imaging surpasses EEG/MEG, aiding neurological research at NUS. Hard disk drives benefit from higher areal density, while quantum sensing integrates with NTU's quantum tech labs.

• Automotive: Current sensing in batteries, position detection in motors.
• Healthcare: Magnetoencephalography (MEG) for epilepsy diagnosis.
• Consumer: Smartphones for compass/orientation, AR/VR tracking.
• Industrial: Non-destructive testing in semiconductors.

The global magnetic sensors market is projected to reach $6 billion by 2036, with Asia-Pacific leading growth.

IMRE's work thrives through partnerships with Singapore universities. Joint labs with NUS on 2D electronics and NTU on flexible sensors accelerate tech transfer. SUTD contributes fabrication expertise, training PhD students in vdW materials. This ecosystem has produced over 200 patents, fostering a talent pipeline for higher ed grads.IMRE's 2D materials group exemplifies this collaboration.

Dr. Kui Yao, IMRE researcher, notes, "Our vdW heterostructures decouple sensitivity from speed, revolutionizing sensing." NUS Prof. Andrew Wee highlights, "This boosts Singapore's materials R&D, creating jobs in higher ed." Industry leaders at STMicroelectronics praise the low-power design for IoT.

Challenges remain: scalability and cost. IMRE addresses this via CVD scaling, targeting commercial prototypes by 2028.

Singapore's electronics sector, 20% of manufacturing GDP, gains from enhanced sensors, potentially adding S$1B in exports. Higher ed benefits via research grants, PhD opportunities. With 5G/6G rollout, these sensors enable smart factories, aligning with Industry 4.0.

IMRE eyes integrating topological insulators for noise-free detection. Collaborations with global labs promise hybrid quantum-classical sensors. By 2030, expect widespread adoption in Singapore's biomedical hub.

For students and researchers, this underscores materials science's vibrancy. Explore opportunities at Singapore research jobs.

Photo by Opt Lasers on Unsplash

• Vs. Cambridge 2D quantum sensor: IMRE's room-temp operation trumps cryogenic needs.
• Vs. NUS hybrid sensor: 200x sensitivity gain, but IMRE adds speed.

Singapore now rivals US/EU in 2D magnetics.