Improved transfer process for fabrication of cantilever with precise air-gap formation

Seo

2018

Unlike lithography-based processes, printed electronics does not require etching, which makes it difficult to fabricate electronic devices with an air gap. In this study, we propose a method to fabricate capacitive air-gap touch sensors via printing and coating. First, the bottom electrode was fabricated on a flexible poly(ethylene terephthalate) (PET) substrate using roll-to-roll gravure printing with silver ink. Then poly(dimethylsiloxane) (PDMS) was spin coated to form a sacrificial layer. The top electrode was fabricated on the sacrificial layer by spin coating with a stretchable silver ink. The sensor samples were then put in a tetrabutylammonium (TBAF) bath to generate the air gap by removing the sacrificial layer. The capacitance of the samples was measured for verification, and the results show that the capacitance increases in proportion to the applied force from 0 to 2.5 N.

Section: Introductionmentioning

confidence: 99%

“…Kanazawa et al fabricated a cantilever structural force gauge using a transfer process. 18) In that work, two glass substrates were prepared, and a top electrode was printed on one of the glass substrates. The bottom electrode and a step layer were printed on another glass substrate.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of a printed capacitive air-gap touch sensor

Seo

2018

“…The process is called "lift-on offset printing (LOOP)". [26][27][28] In principle, the LOOP method incurs no material loss and enables the formation of a hollow structure using a short process. In this paper, we present an efficient process for making a structural addition to the undersurface of a cantilever by enhancing the LOOP method.…”

Section: Introductionmentioning

confidence: 99%

Improved process for forming a three-dimensional undersurface on a printed cantilever

Kanazawa

Kusaka

Yamamoto

et al. 2018

An improvement in the lift-on offset printing process is reported as a means of enabling the structural customization of hollow structures used as moving parts of sensors and actuators. The improved process can add structures to the underside of a hollow structure by modifying the preparation of the pre-structure. As a demonstration, the mechanical displacement of a cantilever in a gravitational acceleration sensor was enhanced by the addition of a proof mass. The improved process can be expected to further produce functionalized hollow structures by an efficient manufacturing process.

“…Based on the aforementioned background, we have developed and reported on a novel transferring method that can fabricate a cantilever using a fully additive process based on printing. 19,20) In this process, a cantilever can be transferred by controlling the drying conditions and the adhesiveness of the printed ink on a temporary substrate. Although the transferred cantilever was limited to a plane structure in the previous studies, the addition of a weight onto the cantilever was frequently used to obtain a high responsiveness.…”

Section: Introductionmentioning

confidence: 99%

One-batch transfer process for the additive manufacturing of a cantilever with a weight

Kanazawa¹,

Kusaka²,

Yamamoto³

et al. 2017

An improved transferring process that can be used to additively fabricate a cantilever with a weight is reported. By using a poly(dimethylsiloxane) template with a cavity relief structure for the weight formation, an increase in the number of process steps was not required. A capacitive acceleration sensor was successfully manufactured using the described process. Enhanced responsiveness of the sensor was clearly shown to result from the effect of the weight. The one-batch transfer process has the potential to significantly simplify the manufacturing process of highly responsive hollow structures and could be applied in the fabrication of various microelectromechanical system sensors.