（二）应用于医疗的量子传感芯片：脑磁探测

本课题组致力于开发应用于医疗领域的量子传感芯片，尤其在脑磁探测方向深耕细作。量子传感器凭借原子、分子、电子、光子等微观粒子的超高灵敏特性，能够对磁场等物理量进行极其精密的测量。为了突破传统量子传感器体积庞大的限制，我们专注于将微光机电系统（MEMS）技术与量子传感技术深度融合，旨在研制高性能、小型化的量子传感芯片，从而极大拓展其在医疗健康领域的应用。

芯片原子磁强计与核心敏感元件制备

我们以芯片原子磁强计为核心，利用原子自旋对磁场的敏感特性，实现fT（飞特斯拉）量级的超高灵敏磁场测量。这使得我们能够对人脑产生的微弱磁场进行精准成像，为阿尔茨海默症的早期诊断、抑郁症及癫痫术前病灶定位、以及未来脑机接口等前沿应用提供强有力的新型工具。通过芯片化技术，我们有望显著缩小现有传感器的体积，提升脑磁等极弱磁信号的空间分辨率，并大幅降低传感器的成本。

本研究的核心优势在于对核心敏感元件的自主制备与集成。我们重点攻克包括：

• MEMS气室：设计与制备高性能微型原子气室，这是实现芯片级原子磁强计的关键所在，确保原子密度和光学传输效率。
• 无磁加热技术：开发创新的无磁加热方案，在维持原子气室工作温度的同时，避免引入额外磁噪声，从而保证测量精度。
• 双平面线圈集成：设计并集成微型双平面线圈，用于产生和控制原子磁强计所需的环境磁场与射频场，实现对原子自旋的精准操控。

通过这些关键元器件的精细加工与高度集成，我们能够构建出小型化、便携式的脑磁影像设备。相较于脑电信号，脑磁信号能够无畸变地穿透颅骨，从而探测到脑深部的精微活动，这对于癫痫病灶的准确识别具有里程碑式的意义。本研究将聚焦于从传感器核心敏感元件制备到整个脑磁系统搭建的全链条研发，研制具有广阔市场前景的新一代脑磁影像设备。该研究得到了西安交通大学医工交叉产教融合平台的有力支持，为项目的深入开展提供了坚实保障。

欢迎仪器、电子、微纳加工、光学工程、生物医学工程等相关专业的优秀硕士生、博士生加入我们的团队，共同攻克脑磁探测领域的国际前沿难题，为人类健康事业贡献力量！

On-chip Quantum Sensors for Medical Applications: Magnetoencephalography (MEG)

Our research group is dedicated to developing quantum sensing chips for medical applications, with a particular focus on Magnetoencephalography (MEG). Quantum sensors leverage the ultra-high sensitivity of microscopic entities such as atoms, molecules, electrons, and photons to precisely measure physical quantities like magnetic fields. To overcome the size limitations of conventional quantum sensors, we concentrate on integrating Micro-Electro-Mechanical Systems (MEMS) technology with quantum sensing, aiming to develop high-performance, miniaturized quantum sensing chips that significantly expand their applications in healthcare.

Chip-scale Atomic Magnetometers and Core Sensing Element Fabrication

At the core of our work is the chip-scale atomic magnetometer, which utilizes the magnetic field sensitivity of atomic spins to achieve ultra-high precision measurements in the femtotesla (fT) range. This enables us to accurately image the faint magnetic fields generated by the human brain, offering a powerful new tool for early diagnosis of Alzheimer's disease, preoperative localization for depression and epilepsy, and future brain-computer interfaces. Through chip-level integration, we expect to substantially reduce the size of existing sensors, enhance the spatial resolution of extremely weak magnetic fields like brain magnetism, and significantly lower sensor costs.

Our research's key strength lies in the independent fabrication and integration of core sensitive components. We are addressing critical challenges, including:

• MEMS Vapor Cells: Designing and fabricating high-performance miniature atomic vapor cells, which are crucial for realizing chip-scale atomic magnetometers by ensuring optimal atomic density and optical transmission efficiency.
• Magnetically Shielded Heating Technology: Developing innovative, magnetically inert heating solutions to maintain the required operating temperature of the vapor cell without introducing additional magnetic noise, thereby preserving measurement accuracy.
• Dual-planar Coil Integration: Designing and integrating miniature dual-planar coils to generate and control the magnetic fields and radiofrequency fields necessary for atomic magnetometers, enabling precise manipulation of atomic spins.

Through the meticulous fabrication and high-level integration of these key components, we aim to construct miniaturized and portable MEG devices. Unlike electroencephalography (EEG) signals, MEG signals can penetrate the skull without distortion, allowing for the detection of subtle activities deep within the brain. This holds monumental significance for accurately identifying epileptic foci. This research focuses on the full spectrum of R&D, from the preparation of core sensitive components to the construction of the entire MEG system, aiming to develop a new generation of MEG imaging equipment with broad market prospects. This study is robustly supported by Xi'an Jiaotong University's Medical-Engineering Cross-Disciplinary Industry-Education Integration Platform, providing a solid guarantee for the project's in-depth development.

We welcome outstanding Master's and Ph.D. students from instrument science, electronics, micro/nano fabrication, optical engineering, biomedical engineering, and related fields to join our team. Together, let's tackle international frontier challenges in brain magnetic detection and contribute to human health!

（三）基于核自旋补偿的运动脑磁测量：

在人体运动状态下进行脑磁测量，是脑科学和神经工程领域的一项重大挑战，也是我们课题组的特色研究方向。本研究获得了国家自然科学基金面向项目支持，旨在突破运动伪影对脑磁信号的干扰，实现更真实、更自然状态下的人脑功能探测。

传统的脑磁测量（MEG）系统通常要求受试者保持静止，以避免运动造成的强大背景干扰磁场。而脑磁信号本身仅有约100 fT的微弱强度。即使在磁屏蔽房内，经过补偿后的残余磁场可控制在1 nT以内，但人体运动引起的磁场变化仍然远超这一范围，严重掩盖了脑部自身的微弱神经磁信号。

针对这一核心难题，我们课题组创新性地提出并正在开发基于核自旋的干扰磁场主动补偿技术。我们利用超极化的核自旋对磁场的超高灵敏度和可操控性，构建一个能够实时感知并抵消运动造成背景磁场变化的补偿系统。这意味着，我们将能够：

• 突破运动限制： 实现对清醒、自由活动个体（如儿童、帕金森患者、运动员等）的脑功能测量，为更广泛的临床诊断和脑科学研究提供可能。
• 提升测量精度： 在复杂动态环境中，依然保持对微弱脑磁信号的高灵敏度探测能力。
• 推动应用前沿： 为脑机接口、神经康复、运动认知等领域的深入研究奠定基础，并有望为阿尔茨海默病、癫痫等疾病的早期诊断和治疗评估提供全新的工具。

 Motion Brain Magnetometry Based on Nuclear Spin Compensation

Measuring brain magnetism during human motion presents significant challenges in the fields of brain science and neural engineering, and it is a distinctive research direction of our group. This research is supported by the National Natural Science Foundation of China (NSFC) for Key Programs, aiming to overcome motion artifact interference with brain magnetic signals and achieve brain functional detection in more realistic and natural states.

Conventional magnetoencephalography (MEG) systems typically require subjects to remain still to avoid strong background interference magnetic fields caused by movement. Brain magnetic signals themselves are extremely weak, approximately 100 fT. Even within a magnetically shielded room, residual magnetic fields can be compensated to within 1 nT; however, magnetic field changes induced by human motion still far exceed this range, severely masking the brain's own subtle neural magnetic signals.

To address this core challenge, our research group has innovatively proposed and is developing an active compensation technology for interference magnetic fields based on nuclear spin. By leveraging the ultra-high sensitivity and controllability of hyperpolarized nuclear spins to magnetic fields, we are constructing a compensation system capable of real-time sensing and canceling background magnetic field changes caused by motion. This initiative will enable us to:

• Break Motion Limitations: Realize brain function measurements in awake, freely moving individuals (e.g., children, Parkinson's patients, athletes), opening possibilities for broader clinical diagnoses and brain science research.
• Enhance Measurement Precision: Maintain high-sensitivity detection capabilities for weak brain magnetic signals even in complex dynamic environments.
• Advance Frontier Applications: Lay the foundation for in-depth research in brain-computer interfaces, neural rehabilitation, and motor cognition, and potentially provide new tools for early diagnosis and treatment evaluation of diseases such as Alzheimer's and epilepsy.

利用此磁强计，实现了灵敏度为3.2fT/Hz^(1/2) 的灵敏度。3.2fT/Hz^(1/2) magnetic field sensitivity has been achieved.