A flexible proximity sensor fully fabricated by inkjet printing

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Sensor Technology

Background:

• Flexible electronics offer advantages in wearable devices and novel sensing applications.
• Traditional sensor fabrication methods often involve complex, costly, and time-consuming processes like photolithography.
• Inkjet printing presents a potential low-cost, direct-patterning alternative for fabricating electronic components on flexible substrates.

Purpose of the Study:

• To propose and demonstrate a fully flexible proximity sensor fabricated exclusively through inkjet printing.
• To investigate the feasibility of using inkjet-printed zinc oxide (ZnO) and nano silver layers for sensor applications.
• To evaluate the sensor's sensitivity to the human body for potential proximity and thermal radiation sensing.

Main Methods:

• Fabrication of a flexible proximity sensor using inkjet printing.
• The sensor structure consists of a ZnO layer between a flexible aluminum bottom electrode and a web-shaped nano silver top electrode.
• Both ZnO and nano silver layers were deposited directly onto the flexible aluminum substrate via inkjet printing, avoiding photolithography and etching.

Main Results:

• A functional flexible proximity sensor was successfully fabricated using a fully inkjet printing process.
• The sensor demonstrated sensitivity to the proximity of the human body.
• The direct patterning capability of inkjet printing eliminated the need for traditional microfabrication steps, reducing complexity and cost.

Conclusions:

• Inkjet printing is a viable and advantageous method for fabricating fully flexible proximity sensors.
• The developed sensor shows promise for applications in proximity sensing and thermal radiation sensing due to its human body sensitivity.
• This low-cost, direct-patterning approach opens avenues for scalable production of flexible electronic sensors.