Evaluation of the Influence of Curing Processes on the Temperature Coefficient of Resistance of Aerosol-Jet-Printed Temperature Sensors in the IEEE Sensors Journal
Product Introduction
Equipment Parameters
I. Abstract of the Paper’s Core Research
- The higher the curing temperature, the more pronounced the reduction in film resistance and the significant improvement in uniformity.
The curing temperature range for silver ink is 100–250°C, while for gold ink it is 275–375°C. As the temperature increases, the maximum reduction in room-temperature resistance reaches 75.2% for silver samples and 71.2% for gold samples. The coefficient of variation of resistance can be reduced by up to 95%, significantly narrowing process‑to‑process variability in mass production.
- The agglomeration of microscopic particles directly determines the temperature‑sensing TCR sensitivity.
High temperature promotes the melting and agglomeration of nanoparticles, leading to a reduction in grain boundaries; the silver TCR increases linearly with temperature, reaching 3.4 × 10⁻³ °C⁻¹ at 250 °C, close to the theoretical value for bulk silver; the gold TCR initially rises with increasing temperature but levels off after 325 °C, peaking at 2.5 × 10⁻³ °C⁻¹, which is lower than the intrinsic coefficient of bulk gold.
- A comprehensive microstructural analysis elucidates the performance differences between two types of ink.
Silver nanoparticles have a lower melting point and can be fully sintered at relatively low temperatures; gold particles, by contrast, require higher temperatures to fuse, and exceeding 325°C can induce internal thermal stresses that give rise to microcracks, thereby compromising stability. SEM imaging clearly demonstrates that particle size continues to increase with rising temperature.
- Wide-temperature-range stable linear temperature-sensing characteristics
Across the entire test range (-10°C to 70°C), the resistance–temperature fit exhibits an R² greater than 0.99, with excellent linearity, meeting the precise temperature‑measurement requirements of industrial and wearable applications.
- The standardized process database can directly guide mass production.
Two optimal sintering windows for the inks are identified: silver at 200–250°C and gold at 300–325°C, balancing high TCR sensitivity with a low risk of thin-film cracking, thereby providing a reusable process standard for the mass production of aerosol‑printed temperature sensors.
II. Complete Preparation and Testing Process for Aerosol Sprays
(1) Complete Preparation and Characterization Workflow for RTD Sensors
- Alumina substrate ultrasonic cleaning with ethanol, followed by dust-free drying;
- Silver ink is atomized by pneumatic atomization, while gold ink is atomized by ultrasonic atomization; serpentine temperature-sensing circuits are printed in batches using aerosol printing.
- After printing, preheat the substrate for 15 minutes to partially remove the solvent, then cure it in a stepwise temperature‑ramped oven at a heating rate of 8°C/min, holding at the final temperature for 60 minutes.
- The linewidth was observed using an optical microscope, and the room-temperature resistance was measured with a four-probe multimeter.
- FE-SEM was used to image the microstructural morphology of the thin-film particles, and ImageJ was employed to analyze particle size distribution.
- Programmable temperature chamber – stepwise temperature control from 10 to 70°C, equipped with a standard Pt100 sensor as a reference; resistance changes are acquired to calculate the TCR coefficient.
(II) Five Core Advantages of Aerosol-Based Processes (Comparison with Lithography and Screen Printing)
- Dual-atomization system compatible with multi-metal nano‑inks
The equipment supports both pneumatic and ultrasonic atomization, is compatible with nano‑suspensions of varying viscosities—silver‑based and gold‑based—and enables a single production line to simultaneously develop two types of temperature‑sensing devices.
- High-precision microscale serpentine electrode fabrication
The aerosol beam can be focused with controllable precision, achieving an average linewidth of 116 μm for silver and 77 μm for gold. The electrode’s length and width are digitally adjustable, enabling adaptation to various temperature‑measurement ranges and sensitivity requirements.
- Maskless Rapid Process Gradient Prototyping
No custom photomasks are required; 16 sets of samples with different curing conditions can be prepared in batch within a short time, enabling efficient completion of orthogonal experiments on sintering parameters.
- Non-contact printing compatible with high-temperature, custom-shaped substrates.
Alumina, ceramics, and high‑temperature PI can all be molded, offering inherent suitability for high‑temperature industrial temperature‑measurement applications.
- Process variables can be analyzed independently.
The printing parameters and the curing temperature are decoupled, allowing for a separate quantitative analysis of the sintering process’s impact on sensing performance while eliminating interference from the printing step, thereby yielding more robust and actionable conclusions.
III. Five Core Technological Innovations of This Study
Innovation 1: Establishing a comprehensive quantitative correlation among sintering temperature, microstructure, and TCR.
Innovation 2: Distinguishing the Differential Sintering Evolutionary Patterns of Gold, Silver, and Ink Materials
Innovation 3 proposes a mass-production sintering window that balances both sensitivity and yield.
Innovative Preparation Protocol for Low-Dispersity Aerosol RTD Standardization
Innovation 5: The general process research paradigm can be extended to other metal inks.
IV. Current Industry Challenges in the Process and Corresponding Breakthrough Solutions
Challenge 1: Ink manufacturers provide only a broad curing window, with no reference to TCR sensitivity.
Challenge 2: At low temperatures, the nanoparticles remain loosely packed, resulting in high film resistance and poor temperature-sensing sensitivity.
Challenge 3: Excessively high sintering temperatures lead to microcracks in the thin film, resulting in reduced device uniformity.
Challenge 4: Aerosol-printed sensors exhibit significant batch-to-batch resistance variability and high temperature measurement errors.
Challenge 5: There is no systematic comparative data on the sintering behavior of gold and silver metallic inks.
V. Future Diversified Industrial Application Scenarios
- Embedded High-Temperature Temperature Sensor for Industrial Equipment
- Wearable medical flexible temperature-sensing patch
- Industry 4.0 Smart Production Line Multi-Point Sensor Array
- Aerospace Micro Lightweight Temperature-Sensing Elements
- University-level R&D Platform for Printed Electronics Technology
Table I Process Parameters Selected for Printing with Two Types of Ink
Figure 1. Examples of fabricated silver electrodes (left) and gold electrodes (right)
Table II: Solidification Temperatures of Prepared Samples for Both Silver and Gold Specimens
Figure 2. Schematic diagram of the experimental setup for evaluating temperature sensitivity. In brief, a computer equipped with a dedicated LabVIEW VI software is used to set the temperature setpoint (Tset) of the climate chamber and to acquire the resistance values of the device under test (DUT) via an array of HP34401A digital multimeters; meanwhile, a commercial temperature sensor measures the actual temperature (Tf) near the DUT.
Figure 3. Resistance changes of samples prepared with silver ink and gold ink at room temperature.
Figure 4. SEM‑based characterization of silver samples cured at (a) 100°C, (b) 120°C, (c) 150°C, (d) 200°C, and (e) 250°C; (f) shows the estimated cluster size as a function of curing temperature.
Figure 5. Results of scanning electron microscopy (SEM) analysis of gold samples cured at (a) 275°C, (b) 300°C, (c) 325°C, (d) 350°C, and (e) 375°C; (f) shows the estimated relationship between aggregate size and curing temperature.
Figure 6. Calibration relationships obtained using (a) silver ink and (b) gold ink at different curing temperatures. The TCR values corresponding to each curing temperature are indicated in the data for (c) silver ink and (d) gold ink, respectively.
Download Materials
Beijing Yunshang Intelligent Manufacturing Technology Co., Ltd.
Hotline(24 hours a day)
Headquarters Address: Room 708, Building 2, HICOOL Industrial Park, Nanfaxin, Shunyi District, Beijing
Follow
Customer service WeChat
WeChat Official Account
COPYRIGHT 2026 Beijing Yunshang Intelligent Manufacturing Technology Co., Ltd.
Powered by 300.cn Privacy Policy
YUNS-123456
Smart Customer Service
WhatsApp：864009005667
Company email：support@chinayuns.com
Telephone：400 900 5667