Browsing by Author "Secor, Ethan B."

Now showing 1 - 2 of 2

AN INKJET PRINTED PIEZORESISTIVE BACK-TO-BACK GRAPHENE TACTILE SENSOR FOR ENDOSURGICAL PALPATION APPLICATIONS
(2017-01-01)
Fu, Yu-Min
;
Chou, Meng-Chuin
;
Cheng, Yu-Ting
;
Secor, Ethan B.
;
Hersam, Mark C.
The paper presents a tactile sensor design mimicking human finger touch to differentiate tissue hardness for endosurgical palpation applications. The sensor comprises two inkjet-printed piezoresistive graphene-based sensing elements linked back-to-back for force and displacement detection, respectively. Experimental results indicate the sensor registers 2.1 and 5.3 mN force feedback from the fat and muscle tissues of pig, respectively, when pressed to the tissues with the same 100 mu m displacement. This difference of similar to 2.5 times in force feedback provides a compelling method by which doctors can more intuitively perceive hardness and tissue differences during endosurgery in comparison with the prior arts.
An Inkjet Printing Technique for Scalable Microfabrication of Graphene-Based Sensor Components
(2020-01-01)
Fu, Yu-Min
;
Chou, Meng-Chuin
;
Kang, Che-Hao
;
Cheng, Yu-Ting
;
Wu, Pu-Wei
This paper presents a versatile and precise graphene patterning technique using the combined process of masking and inkjet printing. A graphene-based structure is fabricated by first defining the structural pattern and position using a masking mold, which can be either electroplated copper or deep reactive ion etching (DRIE) silicon shadow mask, followed by inkjet deposition of graphene ink and lift-off. The hybrid technique can realize high-fidelity, high-resolution graphene-based microstructures including free-standing and cantilever beams, four-point resistive measurement structures, and piezoresistive sensing elements with a minimum line width of similar to 20 mu m. Moreover, this method can facilitate the micropatterning of graphene oxide (GO) and reduced graphene oxide (rGO) on substrates such as polydimethylsiloxane (PDMS) and SiO2/Si for selective cell culturing applications. Owing to the characteristics of low chemical usage, low process temperature and complexity, and high fiexibility and fault tolerance of inkjet printing, this technique demonstrates compelling potential for a variety of biomedical applications.