About

Professor Junhong Chen leads the Junhong Chen Research Group at the University of Chicago, focusing on the multidisciplinary design and discovery of novel nanomaterials for advanced sensing and energy devices. The group combines experimental approaches with first-principles calculations to engineer materials that exhibit unique electronic charge separation and transfer at interfaces, enabling superior device performance. Their research addresses critical needs in low-cost, real-time, sensitive, and selective detection of a wide range of analytes relevant to food-energy-water systems, smart and connected health, communities, the Internet of Things, and next-generation smart infrastructures. These sensors integrate with smartphones and terminals equipped with machine learning and big data analytics to enhance functionality and accessibility. In addition to sensor development, Professor Chen's group works on cost-effective, high-performance energy devices aimed at renewable energy production and storage. The research themes also include scalable nanomanufacturing of electronic devices through inkjet printing and nano-enabled water and air pollution control. Professor Chen's work is highly interdisciplinary, involving collaborative projects in AI-enabled molecular engineering and bio-based compound printing for advanced electronics. His contributions have been recognized through numerous interviews, keynote talks, and listings as a highly cited researcher globally. He holds the Crown Family Professorship of Molecular Engineering and actively participates in national initiatives addressing water security, environmental sustainability, and advanced manufacturing.

Research topics

• Computer Science
• Chemistry
• Nanotechnology
• Materials science
• Artificial Intelligence
• Environmental chemistry
• Waste management
• Environmental science

Selected publications

• Fast sweeping for quantum capacitance spectroscopies of two-dimensional materials with microscale spatial resolution

  Review of Scientific Instruments · 2026-05-01

  article1st authorCorresponding

  The density of states (DOS) of two-dimensional (2D) materials directly influences the performance of solar cells, sensors, and transistors. The quantum capacitance devices allow for the DOS measurement at room temperature while suffering from complex fabrication processes, with a duration of 5-10 days. It would be meaningful to shorten the measurement time to the hour-level to meet the high-throughput characterization demands in both laboratory research and industrial applications. In this work, we have developed a quantum capacitance spectroscopy (QCS) measurement technique with two orders of improved throughput and microscale spatial resolution. The QCS is further applied to sweep a 4 × 4 array DOS in a MoS2 monolayer with a 100 μm step size. It is able to distinguish the Mo and the coexisting Mo/S vacancies in the MoS2, while the photoluminescence and Raman spectra cannot. This QCS enables the rapid characterization of the DOS, paving the way for screening the defect states in the 2D materials and failure analysis in devices.

  PublisherDOI

• Effect of cavity mode matching on the output performance of external-cavity diamond Raman oscillators

  Optics Express · 2025-10-17

  articleOpen access

  Mode matching between the pump beam and the cavity eigenmodes plays a critical role in determining the beam quality and conversion efficiency of laser systems. However, compared to population inversion lasers, research on mode matching in Raman lasers has received less attention. Here, we investigate mode-matching characteristics in an external-cavity diamond Raman laser (DRL), leveraging the superior thermal properties of diamond. By employing quasi-continuous pump sources exhibiting significantly different beam qualities, high beam quality first Stokes laser output was achieved across a wide range of cavity length adjustments designed to modify the intra-cavity mode matching. The dynamic cavity length adjustment range reached 6 mm. Under the condition of a pump beam M 2 factor of 4.5, a beam quality improvement exceeding fourfold was attained. The compatible mode-matching ratio range between the pump beam and the resonant modes was found to be 0.54 to 1.20. Furthermore, the impact of different cavity lengths on the stable laser output power was analyzed. This work demonstrates the outstanding performance of the DRL in generating high beam quality output, along with its high tolerance to variations in pump beam quality and cavity length. The investigation of Raman cavity mode matching provides crucial guidance for laser design.

  PublisherDOI

• Mechanical Properties and Energetic Characteristics of AlTiZrNbTa Refractory High-Entropy Alloy

  Journal of Materials Engineering and Performance · 2025-10-15

  article
  PublisherDOI

• Triple therapy disrupts gut microbiota more severely than quadruple therapy in children with <i>Helicobacter pylori</i> infection

  Journal of Applied Microbiology · 2025-06-01

  articleOpen access

  AIMS: Helicobacter pylori (Hp) infection is associated with gastrointestinal and systemic disorders in children. This study compared the effects of triple versus quadruple antibiotic therapies on gut microbiota in children with Hp infection. METHODS AND RESULTS: Thirty pediatric patients with Hp infection were recruited and randomized into triple or quadruple therapy groups for eradication treatment. Fecal samples were collected before treatment, 2 weeks and 6 weeks post-treatment, followed by 16S rDNA gene sequencing. Baseline gut microbiota showed no significant differences between groups. Triple therapy caused significant disruptions in α-diversity, β-diversity, microbial composition, and metabolic pathways, while quadruple therapy resulted in minimal changes. Post-treatment, quadruple therapy exhibited higher α-diversity, distinct β-diversity, and greater abundance of butyrate-producing bacteria compared to triple therapy. Metabolic pathway analysis also revealed significant differences between the two therapies. CONCLUSIONS: Triple therapy significantly disrupted gut microbiota balance, whereas quadruple therapy had a milder impact in Hp-infected children, preserving microbial diversity.

  PublisherOA PDFDOI

• Pound–Drever–Hall stabilized single-frequency diamond Raman laser with sub-10 kHz linewidth

  Optics Letters · 2025-04-10 · 8 citations

  article

  Benefiting from the exceptional properties of diamond crystals and the absence of spatial hole burning in stimulated Raman scattering, diamond Raman lasers (DRLs) are effective materials for achieving a single longitudinal mode laser output at specific wavelengths. The use of resonant pumping techniques can yield a low-threshold single longitudinal mode DRL output. However, the polarization dependence of the Raman gain in diamond and the birefringence induced by high-power lasers affect the output stability and single longitudinal mode characteristics of Hänsch-Couillaud (HC) frequency-stabilized DRLs. To achieve a highly stable, narrow-linewidth DRL output, this study, for the first time, to the best of our knowledge, employed polarization-insensitive Pound-Drever-Hall (PDH) frequency stabilization technology to resonantly pump an external cavity standing-wave diamond Raman oscillator. By using a narrow-linewidth 1064 nm laser as the pump source and locking the cavity length to the pump frequency, a single longitudinal mode 1240 nm first Stokes laser output of 1.3 W was achieved at a maximum pump power of 8 W. The corresponding center wavelength drift and the RMS of output power over 10 min were 25 MHz and 1.87%, respectively. Additionally, the linewidth of the Stokes laser at a maximum output power is 8.8 kHz, representing the first experimental characterization, to our knowledge, of DRL linewidth under resonant pumping conditions. This work demonstrates that DRLs possess significant advantages and potential for achieving a high-power, high-frequency-stability, narrow-linewidth laser output.

  PublisherDOI

• Dynamic tensile behaviors of 3D woven carbon-carbon composites at elevated temperature

  Journal of Reinforced Plastics and Composites · 2025-07-31 · 2 citations

  articleCorresponding

  The quasi-static and dynamic tensile behavior of three-dimensional (3D) woven carbon/carbon (C/C) composites was investigated at elevated temperatures (room temperature, 600°C, 900°C, and 1300°C). The tests were carried out, respectively, by using a material test machine and a rotary disk Hopkinson bar apparatus equipped with a high-temperature synchronous loading device. The results demonstrate that tensile strength was significantly affected by fiber orientation, strain rate, and temperature. Under identical conditions, the composite’s tensile strength in the XY-direction was significantly higher than that in the Z-direction. Under dynamic loading, the composite exhibited higher tensile strength in both the XY- and Z-directions than under quasi-static conditions, emphasizing a clear positive strain rate effect. Residual thermal stress and oxidation caused the composite’s tensile strength to decrease with the increasing temperature from room temperature to 1300°C.

  PublisherDOI

• BOARD # 455: Stimulating Interdisciplinary Graduate Research Across NSF-NRT Institutions

  2025-08-21

  article
  PublisherDOI

• Machine learning-based prediction model for post-ERCP cholangitis in patients with malignant biliary obstruction: a retrospective multicenter study

  Surgical Endoscopy · 2025-07-09

  articleOpen access

  BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is the preferred palliative treatment for patients with unresectable malignant biliary obstruction (MBO), which can relieve biliary obstruction and prolong survival. Post-ERCP cholangitis (PEC) affects the survival of MBO patients. Early prediction of PEC risk is crucial for developing individualized treatment plans and improving prognosis. Currently, no predictive models exist for clinical practice. This study aims to develop and validate an interpretable machine learning prediction model using multicenter cohorts to predict the risk of PEC. METHODS: We collected data from 2831 unresectable MBO patients who underwent ERCP between January 2011 and December 2023. After screening, data from 1026 patients from the First Hospital of Jilin University served as training and internal test cohorts, while data from 395 patients from the Third Hospital of Jilin University were used as an external validation cohort. Six machine learning methods were employed to construct prediction models. Model performance was compared using various metrics. The SHapley Additive exPlanation (SHAP) method was used to interpret the final model. RESULTS: Among all MBO patients, the incidence of PEC was 9.5% (135/1421). Multivariate analysis identified radiofrequency ablation (OR = 3.62, 95% CI 1.26-10.36), white blood cell count (OR = 1.34, 95% CI 1.12-1.60), moderate jaundice (OR = 3.57, 95% CI 1.06-12.09), and abnormal serum amylase (OR = 3.05, 95% CI 1.36-6.79) as independent risk factors for PEC. Four important variables were selected through machine learning methods: radiofrequency ablation, white blood cell count, severity of jaundice, and serum amylase. Among the six machine learning models, the XGBoost model performed best (training cohort AUC: 0.9654). This model accurately predicted PEC risk in MBO patients in both the internal test cohort (AUC: 0.7670) and external validation cohort (AUC: 0.7270). Calibration curves showed good consistency between predicted and observed risks. Decision curve analysis indicated that the model provided substantial clinical net benefit. CONCLUSION: Based on multicenter, large-sample data, we developed and validated an interpretable XGBoost model for predicting PEC risk in MBO patients. This model helps clinicians identify high-risk patients preoperatively, providing a basis for individualized treatment plans and thereby improving patient prognosis.

  PublisherOA PDFDOI

• Influence of microstructure and loading conditions on the dynamic compressive properties of Ni-based single crystal superalloys

  Journal of Alloys and Compounds · 2025-10-29 · 1 citations

  article
  PublisherDOI

• Research on Optimization of Transmission Schemes for Satellite Communications under Low Signal-to-Noise Ratio Conditions

  2025-04-18

  articleSenior author

  To address the performance bottlenecks of convolutional coding and π/4-DQPSK modulation in satellite communications, this paper proposes an optimized scheme employing Turbo codes combined with QPSK modulation. By redesigning the frame structure, implementing Turbo encoding, and adopting QPSK coherent demodulation, the link performance is significantly enhanced while maintaining compatibility with existing interfaces. MATLAB-based simulations demonstrate that the optimized system achieves a 4.8 dB reduction in required signal-to-noise ratio (SNR) at equivalent bit error rate (BER), validating the superiority of Turbo and QPSK integration. This solution effectively meets low-rate service communication requirements under low-SNR conditions, providing technical guidelines for optimizing FDMA-based satellite voice services.

  PublisherDOI

Recent grants

• Collaborative Research: Engineering Miniaturized Gas Sensors with Hybrid Nanostructures

  NSF · $300k · 2009–2012

• NER: Carbon Nanotubes Coated with Nanoparticles - An Enabling Structure for Nanomanufacturing and Nanodevices

  NSF · $176k · 2006–2008

• SNM: Customized Inkjet Printing of Graphene-Based Real-time Water Sensors

  NSF · $1.5M · 2017–2020

• SGER: A Novel Gas Sensing Platform with Tin Oxide Nanocrystals Supported on a Carbon Nanotube

  NSF · $62k · 2008–2009

• Collaborative Research: Exploration of Graphene-Nanocrystal Metamaterials

  NSF · $264k · 2009–2012

Frequent coauthors

• Shun Mao

  Shanghai East Hospital

  153 shared

• Ganhua Lu

  University of Wisconsin–Milwaukee

  113 shared

• Hongting Pu

  Tongji University

  108 shared

• Zhenhai Wen

  Chinese Academy of Sciences

  74 shared

• Shumao Cui

  University of Wisconsin–Milwaukee

  65 shared

• Xiaoyu Sui

  Qiqihar Medical University

  61 shared

• Kehan Yu

  Nanjing University of Posts and Telecommunications

  57 shared

• Yuqin Wang

  University of Chicago

  57 shared

Education

• Ph.D., Mechanical Engineering

  University of Minnesota System

  2002

Awards & honors

• Fellow of the National Academy of Inventors (NAI)
• Fellow of the Royal Society of Chemistry (RSC)
• Fellow of the American Society of Mechanical Engineers (ASME…
• 2016 Wisconsin Innovation Award