Studying Electrical Conductivity Using a 3D Printed Four-Point Probe Station

Abstract

The design and fabrication of functional scientific instrumentation allows students to forge a link between commonly reported numbers and physical material properties. Here, a two-point and four-point probe station for measuring electrical properties of solid materials is fabricated via 3D printing utilizing an inexpensive benchtop fused-deposition modeling system and designed by standard computer-aided design software. Stainless steel tapestry needles serve as probes for contacting a sample; these are also electroplated in order to study their electrical performance, and provide a framework for discussion of electrical charge transport, contact resistance, and conductivity in materials. A microcontroller board is integrated into the probe and controlled using open-source software. Our robust and simple design provides an instrument that is easily fabricated by students and readily applied to a wide range of classroom settings focused on materials science, mechanical and electrical engineering, as well as solid-state physics and chemistry. This 3D printed probe station costs less than $100 US in materials per unit excluding source meter. We demonstrate that two- and four-point resistance measurements carried out on a solid-state semiconductor differ only by less than 5% in magnitude when compared to data collected using a standard and expensive commercial probe station. Two- and four-point resistance measurements carried out on gold deposited on silicon and on the soft nanostructured organic semiconductor poly­(3,4-ethylenedioxythiophene) result in reproducible and accurate current versus voltage (I–V) curves.

Energy storing bricks for stationary PEDOT supercapacitors

“…The sample holder is a background-free silicon disk rotating at 30 rpm when collecting data with a 0.02° scan step at 40 kV and 40 mA. Current–voltage tests are performed on a 3D printed two-point probe station with two gold probes separated by 2 mm 23 . Water absorption experiments are performed as described in ASTM C67/C67M-18 except brick samples are 1 cm × 0.5 cm × 0.28 cm in size.…”

Biocompatible Nanocomposites Based on Poly(styrene-block-isobutylene-block-styrene) and Carbon Nanotubes for Biomedical Application

“…The electrical conductivity was examined using an automated setup based on a Model 236 digital multimeter (Keithley Instruments). The resistance measurement was performed at a constant current according to the four-point probe test [ 19 ]. Measurements were repeated 5 times.…”

Process–Structure–Property Relationships of Copper Parts Manufactured by Laser Powder Bed Fusion

“…The resistance of the as-built coils was directly measured using a DC four-wire Kelvin resistance measurement meter, as shown in Figure 20. EC was calculated using Equation (6) based on the simplified relationship between the current and the voltage drop (V/I), obtaining the coil resistance, namely Ohm's law [42]:…”

“…To ensure good contact, surface cleaning was performed by lightly hand-filling the coil terminals. Considering the EC was calculated using Equation (6) based on the simplified relationship between the current and the voltage drop (V/I), obtaining the coil resistance, namely Ohm's law [42]:…”