Paper-Based Flexible Taxel Device Using Electrical Contact Resistance Variation for Elasticity Measurement on Biological Objects

Abstract

A taxel device on flexible substrates based on the electrical contact resistance (ECR) variation mechanism is developed. The proposed taxel device consists of one top and one bottom substrates, which are coated with conductive polymer then face-to-face assembled. The device is tested with different substrate materials to show the viability of the ECR variation mechanism. It is found that when paper is used as the substrate material, because of its exclusive features of surface roughness and material compressibility, the ECR variation mechanism is greatly enhanced and the device exhibits higher sensitivity and larger working pressure range. Practical applications are investigated in elasticity measurement on phantom samples and biological tissues. The results are promising with our taxel device made on flexible substrates being capable of integration onto surgical tools and the potential to realize the psychical property of biological tissues.

Retracted: Development of a Highly Sensitive Wearable Tactile Sensor on Fabric by Using Conductive Inks Based on Electrical Contact Resistance (ECR) Change Mechanism

“…On the other hand, in a previous research of our group, the ECR mechanism was employed on the paper‐based bottom substrate and the top substrate made by the PET coating on PEDOT:PSS, however, although the PEDOT:PSS possessed the high conductivity(sheet resistance 40 Ω sq −1 ), the PET film suffer the lower compressibility (2.43 × 10 −10 ) than the fabric (3.5 × 10 −7 ), [ 30 ] thus the pressure range (MPa) was higher than this work (kPa) owing to the deformation behavior in high pressure. Whereas, this work created the pillar structure in ≈10 µm height by two‐step printing, leading to high roughness variation (microscale) rather than previous work (nanoscale) and leading high ECR variation, causing the high resistance drop (Δ R ≈ 4 kΩ) in the low‐pressure region (<2 kPa).…”

“…For example, our group previously presented a tactile sensor on paper and PET substrates, based on the electrical contact resistance (ECR) variation mechanism with enhanced sensitivity. [ 30 ] Other researchers employed the contact resistance for pressure sensing by creating the structure substrates to enhance the sensor sensitivity, including pyramid PDMS structures with a poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) coating, microstructures formed by using silk molding, and microdome structures on the PDMS substrates using porous molds. [ 31–34 ] However, these techniques mostly require either semiconductor fabrication or other complicated processes that may not be feasible for practical applications.…”

Origami-Inspired Conductive Paper-Based Folded Pressure Sensor with Interconnection Scaling at the Crease for Novel Wearable Applications

“…The sensing mechanism for the sensor is electrical contact resistance (ECR) variation mechanism which has been previously reported. − ECR is represented by the resistance between two conductive surfaces. The electrical current can pass through the contact points at the interface, as shown in Figure b.…”

Review of Low-Cost 3D Bioprinters: State of the Market and Observed Future Trends

“…6 ). For example, they are used to print silk fibroin, a material for biomedical devices; 164 cell-laden poly- l -lysine mixed with fibronectin; 165 PLA; 166 the conductive polymer composite PEDOT:PSS; 167 pattern polyethylene glycol (PEG) and polymethyl methacrylate (PMMA) on a carbon-fiber mesh; 168 and UV-curable silicone elastomers. 169…”