Needle-Type Microsensor Made by 3D Printing and Localized 3D Electroless Plating

Conventional needle-type sensors are made of glass, which presents issues such as high manufacturing costs due to manual fabrication, a limited range of material properties, and low flexibility in needle shape design. In this study, we attempted to address the issue by utilizing 3D printing for fabrication. To fabricate a sensing electrode, we devised a method which can locally metallize a needle tip using electroless plating, localized 3D electroless plating. We fabricated a needle-type dissolved oxygen sensor and confirmed that the sensor has a short response time of 6 seconds and a response range of up to 260 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu \mathrm{M}$</tex>, which is equivalent to a commercial one, indicating the effectiveness of our proposed metallization method.