Next Article in Journal
Analysis of the Relationship between Turning Signal Detection and Motorcycle Driver’s Characteristics on Urban Roads; A Case Study
Next Article in Special Issue
Wearable Sensor-Based Human Activity Recognition via Two-Layer Diversity-Enhanced Multiclassifier Recognition Method
Previous Article in Journal
Attitude Measurement for High-Spinning Projectile with a Hollow MEMS IMU Consisting of Multiple Accelerometers and Gyros
Previous Article in Special Issue
Motion Artifact Reduction for Wrist-Worn Photoplethysmograph Sensors Based on Different Wavelengths
Article Menu
Issue 8 (April-2) cover image

Export Article

Open AccessArticle

Characteristics of an Implantable Blood Pressure Sensor Packaged by Ultrafast Laser Microwelding

1
Department of Electronics and Control Engineering, Hanbat National University, Daejeon 34158, Korea
2
Department of Laser and Electron Beam Application, Korea Institute of Machinery and Materials, Daejeon 34103, Korea
*
Authors to whom correspondence should be addressed.
Sensors 2019, 19(8), 1801; https://doi.org/10.3390/s19081801
Received: 7 February 2019 / Revised: 11 April 2019 / Accepted: 13 April 2019 / Published: 15 April 2019
(This article belongs to the Special Issue Wearable and Implantable Sensors and Electronics Circuits)
  |  
PDF [2658 KB, uploaded 22 April 2019]
  |  

Abstract

We propose a new packaging process for an implantable blood pressure sensor using ultrafast laser micro-welding. The sensor is a membrane type, passive device that uses the change in the capacitance caused by the membrane deformation due to applied pressure. Components of the sensor such as inductors and capacitors were fabricated on two glass (quartz) wafers and the two wafers were bonded into a single package. Conventional bonding methods such as adhesive bonding, thermal bonding, and anodic bonding require considerable effort and cost. Therefore CO2 laser cutting was used due to its fast and easy operation providing melting and bonding of the interface at the same time. However, a severe heat process leading to a large temperature gradient by rapid heating and quenching at the interface causes microcracks in brittle glass and results in low durability and production yield. In this paper, we introduce an ultrafast laser process for glass bonding because it can optimize the heat accumulation inside the glass by a short pulse width within a few picoseconds and a high pulse repetition rate. As a result, the ultrafast laser welding provides microscale bonding for glass pressure sensor packaging. The packaging process was performed with a minimized welding seam width of 100 μm with a minute. The minimized welding seam allows a drastic reduction of the sensor size, which is a significant benefit for implantable sensors. The fabricated pressure sensor was operated with resonance frequencies corresponding to applied pressures and there was no air leakage through the welded interface. In addition, in vitro cytotoxicity tests with the sensor showed that there was no elution of inner components and the ultrafast laser packaged sensor is non-toxic. The ultrafast laser welding provides a fast and robust glass chip packaging, which has advantages in hermeticity, bio-compatibility, and cost-effectiveness in the manufacturing of compact implantable sensors. View Full-Text
Keywords: implantable blood pressure sensor; ultrafast laser; glass welding; direct bonding; MEMS hermetic packaging implantable blood pressure sensor; ultrafast laser; glass welding; direct bonding; MEMS hermetic packaging
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Kim, S.; Park, J.; So, S.; Ahn, S.; Choi, J.; Koo, C.; Joung, Y.-H. Characteristics of an Implantable Blood Pressure Sensor Packaged by Ultrafast Laser Microwelding. Sensors 2019, 19, 1801.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top