Resistive characterization of soft conductive PDMS membranes for sensor applications

Abstract

Conductive PDMS is used as an active sensing element in many sensor applications. The resistive characterization of Carbon Black (CB) filled soft conductive PDMS (Poly-Di-Methyl-Siloxane) membranes is reported in this paper. The conductive membranes are fabricated on a measurement template. A simple two point resistance measurement scheme, connected to the measurement template measures the surface resistivity of the fabricated membranes. As expected, the resistivity of the membranes decreases with increase in CB concentration. The surface resistivity of membranes fabricated using CB-PDMS composite and CBMethanol-PDMS composite is compared. It is observed that dispersion of CB particle in methanol prior to the preparation of conductive PDMS has following advantages. 1) Low percolation threshold 2) Higher conductivity 3) Better surface profile. The CB filled conductive PDMS membranes show piezo resistivity. The resistance of the membranes increases with increased pressure. Higher values of piezo resistivity coefficients are observed at low CB concentration. The effect of the ambient temperature on the membrane resistance is also discussed. The conductive membranes show a Positive Temperature Coefficient (PTC) and the value of the coefficient increases with a decrease in concentration.

Large-area flexible MWCNT/PDMS pressure sensor for ergonomic design with aid of deep learning

“…The MWCNT/PDMS sensing unit (7.5 wt.%) can make a rapid response to external pressure. To the best of our knowledge, the prepared MWCNT/PDMS sensor has demonstrated excellent overall performance in recent years [36][37][38][39][40][41][42][43]. And the parameters, dimensions and properties of the reported pressure sensors are shown in table S3.…”

Characterization of Carbon Black Filled PDMS-Composite Membranes for Sensor Applications

“…Hence, most known results are not useful for applications which require thin and soft CPDMS membranes. This paper discusses the fabrication and characterization of thin soft CPDMS membranes in view of regarding sensor applications [23].…”

Development of a polymer based fully flexible electrode tip for neuronal micro-stimulation applications

“…High flexibility in electronics systems was reported in the literature by using thin film systems, 10,15) conductive polymers such as Ag-powder or carbon-black doped poly(dimethylsiloxane) (PDMS), 16) and liquid metal alloys liquid which are at room temperature, such as mercury or Galinstan. 17) Where thin films systems are indicated for deposition on external surface of the tissues, 10,15) the possible encapsulation of liquid alloy or conductive polymers within a functionalized polymer volume allows its use into insertable systems.…”

“…8,11,14) This volume can easily be patterned to a high degree using mask and mold replicating techniques, allowing the development of numerous designs for specific applications. While fairly long conductive polymer lines and designs can hardly suffer from charge transfer due to the random distribution of the particles into the polymer matrix 16,18,19) liquid metal alloys are completely suitable for wide surface 17) and wiring applications. 20) Indeed, where conductivity losses into a conductive polymer feature are highly probable, due to the possible lack of a conductive particles path in some sections of its design, liquid alloys behave as standard metals, thus presenting in any case a good conductivity.…”