This work presents ThermoMesh, a passive thin-film thermoelectric mesh sensor designed to detect and characterize spatio-temporally sparse heat sources through conduction-based thermal imaging. The device integrates thermoelectric junctions with linear or nonlinear interlayer resistive elements to perform simultaneous sensing and in-sensor compression. We focus on the single-event (1-sparse) operation and define four performance metrics: range, efficiency, sensitivity, and accuracy. Numerical modeling shows that a linear resistive interlayer flattens the sensitivity distribution and improves minimum sensitivity by approximately tenfold for a $16\times16$ mesh. Nonlinear temperature-dependent interlayers further enhance minimum sensitivity at scale: a ceramic negative-temperature-coefficient (NTC) layer over 973--1273~K yields a $\sim14{,}500\times$ higher minimum sensitivity than the linear design at a $200\times200$ mesh, while a VO$_2$ interlayer modeled across its metal--insulator transition (MIT) over 298--373~K yields a $\sim24\times$ improvement. Using synthetic 1-sparse datasets with white boundary-channel noise at a signal-to-noise ratio of 40~dB, the VO$_2$ case achieved $98\%$ localization accuracy, a mean absolute temperature error of $0.23$~K, and a noise-equivalent temperature (NET) of $0.07$~K. For the ceramic-NTC case no localization errors were observed under the tested conditions, with a mean absolute temperature error of $1.83$~K and a NET of $1.49$~K. These results indicate that ThermoMesh could enable energy-efficient embedded thermal sensing in scenarios where conventional infrared imaging is limited, such as molten-droplet detection or hot-spot monitoring in harsh environments.

翻译：本文介绍了一种名为ThermoMesh的无源薄膜热电网格传感器，其通过传导式热成像技术检测和表征时空稀疏热源。该器件将热电结与线性或非线性层间电阻元件集成，实现同步传感与传感器内压缩。我们聚焦于单事件（1-稀疏）运行模式，定义了四项性能指标：范围、效率、灵敏度和精度。数值建模表明，线性电阻层间结构可平坦化灵敏度分布，使$16\times16$网格的最小灵敏度提升约十倍。非线性温度依赖型层间结构进一步增强了规模化后的最小灵敏度：在973–1273 K温度区间内，采用陶瓷负温度系数（NTC）层的$200\times200$网格，其最小灵敏度比线性设计高出约$\sim14{,}500$倍；而基于VO$_2$在298–373 K温度区间内金属-绝缘体相变（MIT）特性的层间结构，则实现了约$\sim24$倍的改进。在信噪比为40 dB且含白噪声边界通道的合成1-稀疏数据集测试中，VO$_2$方案实现了98%的定位精度、0.23 K的平均绝对温度误差及0.07 K的噪声等效温度（NET）。陶瓷NTC方案在测试条件下未出现定位误差，平均绝对温度误差为1.83 K，NET为1.49 K。结果表明，在传统红外成像受限的场景（如高温环境下的熔滴检测或热点监控）中，ThermoMesh能够实现节能型嵌入式热传感。