Session: Government Agency Student Posters

Paper Number: 173002

Direct Ink Writing Silver/pvdf/mxene Multilayered Multifunctional Tactile Sensor 

The growing demand for intelligent sensing systems in healthcare, robotics, and environmental diagnostics necessitates multifunctional platforms capable of detecting both physical stimuli and biochemical markers in real-time. Traditional thin-film fabrication techniques such as sputtering or spin-coating often fall short in integrating multiple sensing modalities into a single device due to limitations in patterning complexity, material compatibility, and scalability. To address these challenges, we propose a novel sensor system fabricated via Direct Ink Writing (DIW), which enables layer-by-layer deposition of functional inks into complex architectures. The primary objective of this research is to develop and demonstrate a DIW-fabricated multilayered tactile sensor capable of simultaneous proximity, pressure, and biomarker sensing within a unified device.

Our contribution lies in the rational design and integration of printable materials—silver, polyvinylidene fluoride (PVDF), and MXene (Ti₃C₂)—to create an interdigitated electrode (IDE) pattern for physical sensing, and a three-electrode pattern for biochemical detection. This trilayer structure combines the mechanical compliance of PVDF, the electrical conductivity and functional surface chemistry of MXene, and the robust interfacing properties of silver. We demonstrate that the sequence and configuration of these layers critically affect the sensor’s performance, and we systematically investigate multiple configurations to optimize signal response and device robustness.

The sensor was fabricated using DIW with customized inks: silver paste was printed as the bottom electrode, followed by PVDF and MXene composite layers, forming either IDE or three-electrode structures. Capacitive and piezoresistive measurements were carried out using LCR meters and source meters under controlled mechanical loading. For biosensing, surface functionalization was performed by immobilizing H1N1 antibodies on the MXene layer via APTES chemistry, and electrochemical detection was conducted using cyclic voltammetry (CV) in PBS.

Experimental results show that the IDE structure with the Silver/PVDF/MXene configuration offers high-performance proximity and pressure sensing. The proximity mode achieves a sensitivity (Kp) of up to 269.7 for conductive targets, while the pressure mode delivers dual responses: a capacitive sensitivity of 0.56 pF N⁻¹ and a piezoresistive sensitivity of 22.5 N⁻¹ over a range of 7–11 N. For biosensing, the three-electrode configuration demonstrates clear, concentration-dependent electrochemical signals for H1N1 detection, with a linear response from 250 to 250,000 copies mL⁻¹.

To showcase real-world applicability, we integrated the sensing modules into a robotic arm. The IDE pattern provided real-time proximity and pressure feedback during object manipulation, while the biosensor detected the presence of viral biomarkers on object surfaces. This integrated system validates the potential of DIW-based multifunctional sensors for applications such as security screening, intelligent diagnostics, and human-machine interfacing.

In conclusion, this work advances the field of flexible electronics by demonstrating a DIW-fabricated, multilayered sensing platform capable of simultaneous mechanical and biochemical detection. The combination of material innovation, rational architectural design, and practical robotic integration highlights the promise of this approach for future multimodal sensing systems in complex, dynamic environments.

Presenting Author: Yun Li Villanova University

Presenting Author Biography: PhD Candidate
Hybrid Nano-Architectures and Advanced Manufacturing Laboratory
Mechanical Engineering
Villanova University

Authors:

Yun Li Villanova University
Jiaoli Li Texas A&M University
Kathryn Feddish Villanova Unversity
Chenglin Wu Texas A&M University
Bo Li Villanova University