Package, Process & Microassembly

Research that includes:

  • Low temperature MEMS-on-CMOS Silicon-Germanium process for adding MEMS to finished CMOS wafers or dice
  • Silicon Carbide process for adverse environment MEMS and high frequency RF resonators
  • Localized bonding: eutectic, fusion, solder, laser, inductive, rapid thermal processing, and ultrasonic; suitable for device level or wafer level packaging or sealing applications to plastic, glass, silicon and Bio materials, including liquid encapsulation
  • Fluidic microassembly for post-process combining of dissimilarly processed microdevices
  • Carbon nanotube and silicon nanowire directional growth in post-process, low ambient temperature environments
  • Stiction mitigation for MEMS

Eliminating Structural Defects in Large Area Mechanical Metamaterials via Hot Lithography in Large-Area Projection Micro-Stereolithography

David Hahn
Vatsa Gandhi
Hauchen Cui
Angkur J.D. Shaikeea
Zhenpeng Xu
Zac Gwennap
Vikram Deshpande
Rayne Zheng
2025

Additive manufacturing has enabled the creation of new classes of architected meta-materials with exceptional structural and functional properties. Large-area projection micro-stereolithography (LAPµSL) has the potential for producing large volume metamaterials with millions of micro-scale unit cells and multiple orders of magnitude in length scales. Nevertheless, as part size grows with increasing number of unit cells, probability of finding embedded defects becomes significantly higher. Structural defects, such as internal cracks and non-uniformity embedded within networks of micro-scale...

An RFID-inspired One-step Packaged Multi-mode Bio-analyzer with Vacuum Microfluidics for Point-of-Care Diagnostics

Yan-Ting Hsiao
Ya-Chen (Justine) Tsai
Wei Foo
Hung-Yu Hou
Yun-Chun Su
Yueting Lily Li
Jun-Chau Chien
2025

Current clinical practice for detecting low-concentration molecular biomarkers requires sending samples to centralized labs, leading to high costs and delays (Fig. 20.3.1). Recent developments in molecular diagnostics thus aim to enable point-of-care (POC) detection directly at or near the patient's location [1]–[2]. The most successful POC technology to date is the paper-based lateral-flow assay (LFA) [3]–[4]. Examples include pregnancy tests that sense progesterone and SARS-CoV-2 rapid antigen tests. However, paper-based assays generally provide binary results or limited quantitative...

BPNX1018: Free Surface Investigation in Large-Area Projection Micro Stereolithography

David Hahn
2024

This project seeks to additively manufacture micro-architected cellular solids in high resolution, large area in hundreds of millimeters, containing millions of unit cells which are defect-free.

Project is currently funded by: Federal

Project ended 08/31/2024

BPNX1046: Multi-Material DLP Printing for 3D Electronics via Selective Deposition

Shuo Zhang
David Hahn
Haotian Lu
Ju Young Park
Wenjie (Jeff) Li
Jiayan Zhang
2025

The development of 3D MEMS devices has enabled innovative sensor designs with enhanced functionality, yet conventional fabrication methods often impose geometric and process limitations. This work presents a micro-3D-printed tactile sensor, integrating 3D piezoelectric, capacitive, conductive and dielectric elements with a compliant mechanism to achieve high sensitivity and force decoupling capability. The sensor is fabricated using a multi-material digital light processing (DLP) method, followed by selective metallization to define conductive regions, enabling seamless...

BPNX1012: All-Dielectric Integrated Microlens Couplers for Wafer-Scale Packaging

Sirui Tang
Jianheng Luo
Johannes Henriksson
2025

Despite the widespread use of silicon photonics, fiber coupling remains a major challenge in mass production. Our group has demonstrated integrated microlens couplers (IMCs) as an efficient, broadband, and polarization-insensitive solution for wafer-scale fiber-to-chip coupling, with a previously achieved free-space loss of 0.6 dB.

In this project, we are transitioning from polymer-based to hard-material IMCs, fabricating microlens using SiON and utilizing anisotropic etching to transfer the lens pattern from PR to SiON. By optimizing the oxide-to-nitride ratio, we minimized...

BPN984: Large-Area Processable Two-Dimensional Material Films

Naoki Higashitarumizu
Theodorus Jonathan Wijaya
Hyong Min Kim
Shu Wang
Kyuho Lee
2025

Black phosphorus (BP) is a promising material for optoelectronic applications due to its direct bandgap at all thicknesses, and low Auger recombination coefficient at high carrier densities. BP, being a two-dimensional material, lacks scalability, for which techniques for its large-area processing are important. In this work, we find methodologies to utilize this material for large-scale optoelectronic applications.

Project ended 05/31/2025

BPN735: Walking Silicon Microrobots

Yichen Liu
Daniel Lovell
Alexander Alvara
Dang Le
2025

We aim to develop a family of autonomous silicon-based robotic insects that integrate actuation, computation, and power within a single platform. A silicon-on-insulator (SOI) device serves as the foundation, enabling electrostatic actuators that drive silicon linkages fabricated directly in the device layer. Electrostatic actuation provides a key advantage at the microscale, offering low power consumption suitable for energy harvesting and autonomous operation. Computation and communication are enabled by the Single Chip Micro Mote (SCuM, BPN803), while a Zappy2 chip with integrated solar...

BPNX1051: Multifunctional Smart Contact Lens Sensing Platform

Yifei Zhan
2025

The evolution of contact lens technology is rapidly transforming these simple vision-correcting devices into advanced, multifunctional platforms. By embedding innovative sensor technologies onto contact lenses, it becomes possible to continuously monitor a person’s own well-being in a comfortable and non-invasive way. In this work, we explore the possibility of creating a multifunctional smart contact lens sensing platform that can one day help people easily track important health information, offering new ways to stay connected with their bodies without interrupting daily life.

...

Subtractive Microfluidics in CMOS

Wei-Yang Weng
Alexander Di
Xiang Zhang
Ya-Chen (Justine) Tsai
Yan-Ting Hsiao
Jun-Chau Chien
2024

This paper introduces a microfluidics platform embedded within a silicon chip implemented in CMOS technology. The platform utilizes a one-step wet etching method to create fluidic channels by selectively removing CMOS back-end-of-line (BEOL) routing metals. We term our technique “subtractive” microfluidics, to complement those fabricated with additive manufacturing. Three types of structures are presented in a TSMC I80-nm CMOS chip: (1) passive microfluidics in the form of a micro-mixer and a 1: 64 splitter, (2) fluidic channels with embedded ion-sensitive field-effect transistors (ISFETs...

BPN985: Multimaterial Nanoscale 3D Printing

Daniel Teal
2024

We propose a new multimaterial direct-write printing technique with projected sub-micron resolution. Inorganic nanoparticles (≈1-10nm) of common microfabrication materials are electrically charged, manipulated electromagnetically in vacuum with an ion trap, and shot toward a substrate where they deposit onto a part under construction, similar to PVD methods. To date, we have successfully demonstrated basic multimaterial deposition. Eventually, this ion printing technology could allow rapid prototyping of integrated circuits and MEMS.

Project ended: 12/20/2024