石墨烯柔性傳感器陣列的應(yīng)用受兩大限制制約：現(xiàn)有制備方法難以實(shí)現(xiàn)高空間分辨率，且缺乏面向?qū)嶋H應(yīng)用的系統(tǒng)級集成方案。為應(yīng)對這些挑戰(zhàn)，本文，深圳技術(shù)大學(xué)賈原 副教授、天津師范大學(xué)王程 副教授、哈爾濱工業(yè)大學(xué)Hao Sun等研究人員在《ADVANCED SENSOR RESEARCH》期刊發(fā)表名為“Ultrathin Graphene Strain Sensor Arrays for High-Sensitivity Multifunctional Sensing with Millimeter-Scale Resolution”的論文，研究提出基于超薄石墨烯應(yīng)變傳感器陣列的全集成平臺(tái)。該陣列采用化學(xué)氣相沉積法生長的石墨烯與自上而下微加工技術(shù)，制備于5微米厚聚酰亞胺基板上。通過4×4布局與1mm單元間距設(shè)計(jì)，實(shí)現(xiàn)約64units cm?2的器件密度，從而達(dá)到毫米級空間分辨率。

該平臺(tái)整合了完整的開發(fā)流程，涵蓋傳感器陣列制造、柔性電路設(shè)計(jì)、信號(hào)控制及數(shù)據(jù)采集。耐久性測試顯示其在5000次彎曲循環(huán)中性能穩(wěn)定。應(yīng)變靈敏度測量表明，在0.8%應(yīng)變下最大應(yīng)變系數(shù)達(dá)144，動(dòng)態(tài)測試則呈現(xiàn)0.2秒的快速響應(yīng)時(shí)間與0.16秒的松弛時(shí)間。該平臺(tái)可可靠解析局部壓力分布、監(jiān)測動(dòng)脈脈搏波形并識(shí)別表面曲率，充分展現(xiàn)其多功能傳感能力。這些成果證實(shí)了該平臺(tái)在可穿戴健康監(jiān)測、柔性機(jī)器人及新一代柔性電子設(shè)備領(lǐng)域的實(shí)際應(yīng)用可行性。

2圖文導(dǎo)讀

圖1、Structure, sensing mechanism, and fabrication process of the sensor. a) The photograph of the strain sensor array; b) schematic illustration of the work mechanism; c) schematic illustration of sensor's fabrication process; d) 2D and 3D AFM micrograph of the PI film; e) microscopic image of the strain sensor array; e) Raman spectrum of the purchased CVD graphene; f) SEM micrograph of the purchased graphene.

圖2、Data acquisition system. a) Photograph of custom DAQ and flexible printed circuit (FPC); b) schematic diagram of the Custom data acquisition (DAQ)board and the electrode lead-out (ELO) board; c) block diagram of the working principle of the main program in PC and sub program in the microcontroller.

圖3、a) Durability of the strain sensor in bending–release cycles, photograph inserted on the right showing the bending and flattening stage of the sensor; b) comparison of strain response between the strain sensor and a commercial metal strain gauge under identical test conditions; c) consistency inspection of 16 strain sensors; d) responses of the sensor to diverse radii curvature; e) response/recovery times of the sensor.

圖4、a) Photograph of testing and the radius measurement of the cylindrical object; b) schematic diagram of the row and column indexing of the sensor array; c) 3D bar charts of the sensor array responses to strain applied at six different regions, accompanied by schematic illustrations of the corresponding pressing points.

圖5、a) The acquisition process of pulse waveforms; b) pulse waveforms detection results; c) comparison of pulse signals at seven random feature points before and after 24 h; d) pulse waveforms from four volunteers.

圖6、3D bar charts and contour plots of sensor array responses to objects with different surface curvatures.

3小結(jié)

一種基于石墨烯的完全集成應(yīng)變傳感器陣列平臺(tái)已在超薄聚酰亞胺基板上成功開發(fā)，實(shí)現(xiàn)了高空間分辨率、機(jī)械順應(yīng)性和應(yīng)變靈敏度的理想組合。通過自上而下的微加工技術(shù)，將16個(gè)傳感單元制備成0.5×0.5 cm2陣列，密度達(dá)≈64個(gè)器件/cm2。該陣列在5000次彎曲循環(huán)中表現(xiàn)穩(wěn)定，并在0.8%應(yīng)變下實(shí)現(xiàn)144的最大應(yīng)變系數(shù)。局部載荷測試證實(shí)其具備毫米級分辨率且串?dāng)_極低。應(yīng)用級驗(yàn)證包括脈搏波形監(jiān)測與曲率微分測試，證實(shí)了該平臺(tái)的多功能傳感能力。這些成果凸顯了超薄基板在提升機(jī)械適應(yīng)性與傳感精度的有效性。該平臺(tái)為可穿戴電子設(shè)備、機(jī)器人皮膚及人機(jī)界面中的柔性傳感提供了可擴(kuò)展且可靠的解決方案。未來研究將聚焦陣列規(guī)模化與片上信號(hào)處理，以實(shí)現(xiàn)高吞吐量的智能觸覺傳感。

文獻(xiàn)：

https://doi.org/10.1002/adsr.202500089