1. Lecture 9 Fundamentals of Multiscale Fabrication Applications I:
(Bio)MicroElectroMechanical Systems
Kahp-Yang Suh
Associate Professor
SNU MAE

2. Applications of multiscale systems
Multifunctional nanomaterials (particles, tubes, composites,…)
Synthesis is now highly advanced
Integration issues are yet to be solved
(Bio)Microelectromechanical systems
Sensors/actuators: micro/nanoscale
Detection/measurement: meso/macroscale
Biomimetic multiscale structures
Many length scales and hierarchy
Adapted to each function and mechanism
Micro- and Nanofluidics
Surface/interfacial effects are dominant
Fabrication is still challenging
Photonic and energy devices
Efficiency is limited by defects and many interfaces
Material issues are getting more important

3. ► Multiscale structures for various applications
Biomimetic surfaces
Photonic devices
Nature Nanotechnology, 2007
Langmuir, 2006
Electronic devices
Micro/nanofluidics
APL, 1999
SCIENCE, 2000

4. What are microelectromechanical systems (MEMS)?
The term MEMS refers to a collection of microsensors and actuators which can sense its environment and have the ability to react to changes in that environment with the use of a microcircuit control. They include, in addition to the conventional microelectronics packaging, integrating antenna structures for command signals into micro electromechanical structures for desired sensing and actuating functions. The system also may need micropower supply, micro relay and microsignal processing units. Microcomponents make the system faster, more reliable, cheaper and capable of incorporating more complex functions.
cf) Human body
ex) RF-MEMS: MEMS for RF integrated circuits
BioMEMS: Biological sensing or actuation
Micro-opto-electromechanical systems (MOEMS)
Micro total analysis systems (TAS)

5. ‘Miniaturization engineering’ is a more appropriate name than MEMS, but the name MEMS is more popular. It involves a good understanding of scaling laws, manufacturing methods and materials. Initially it involved mostly Si and mechanical sensors (e.g., pressure, acceleration, etc). Miniaturization engineering or MEMS (NEMS) applied to biotechnology is called BIOMEMS (BIONEMS).
From MEMS to BioMEMS
MEMS: MicroElectroMechanical Systems NEMS: NanoElectroMechanical Systems

7. Device fabrication
A material to create the device – Silicon, Glass, Polymer, Metal…
A process to follow – Micromachining, Nanofabrication…
Process characteristics - Reproducible - Scalable - Inexpensive - Environmentally friendly
Tools to create the device – Lithography, Bonding…
Tools to examine and verify the device – Microscopy, Electrical analysis …
Packing
Integration methods and tools

8. MEMS: Smart Systems Microsystems or MEMS System Techniques
Integrateable Sensors
Integrateable Actuators
Process Engineering
Medical Technology
Automotive Technology
Security & Environmental
Household & Office Tech.
Microsystems or MEMS
Micro
Techniques
Materials
& Effects
Signal Processing Components

9. Microelectronics vs. MEMS
Microsystems (Silicon-based MEMS)
Uses single crystal silicon die, silicon compound, and plastics
Single crystal silicon die, GaAs, quarts, polymers, metals
Transmits electricity for specific electrical functions
Performs biological, chemical, electromechanical functions
Stationary structures
May involve moving components
Primary 2-D structures
Complex 3-D structures
Complex patterns with high density over substrates
Simpler patterns over substrates
Fewer components in assembly
Many components to be assembled
IC die is completely protected from contacting media
Sensor die is interfaced with contacting media
Matured IC design methodology
Lack of engineering design methodology and standards
Large number of electrical feedthroughs and leads
Fewer electrical feedthroughs and leads
Industrial standards available
No industrial standards to follow
Mass productions
Batch production or on customer-needs basis
Fabrication techniques are proved and well documented
Many microelectronics fabrication techniques used
Manufacturing techniques are proved and well documented
District manufacturing techniques
Packaging technology is relatively well established
Packaging technology is at the infant stage

10. What can MEMS do?

11. What else can MEMS do?

12. Digital Light Processingtm (TI DMD, 1987)
Microfabricated digital mirror
High-Brightness (vs. LCD)
High-Resolution

13. ADXL Accelerometer Electro Mechanical System On Chip Compact
High Performance (linearity, sensitivity)
Low cost

14. Automotive Applications
Navigation Gyroscope
Air bag XL
Silicon Nozzles
Tire pressure sensor

15. Aerospace Applications

16. Industrial Applications

17. Customer…

18. MEMS vs. BIOMEMS

19. Definition of BioMEMS From a systemic aspect: From a component aspect:
BioMEMS usually contains sensors, actuators, mechanical structures and electronics. Such systems are being developed as diagnostic and analytical devices.
- Suzanne Berry, TRENDS in Biotechnology (2002)
From a component aspect:
BioMEMS is the research of microfabricated devices for biological applications.
- Tejal A. Desai, Biomolecular Engineering (2000)
MEMS technology is an engineering solution for biomedical problems.
Bio-chip can be used for diagnosis, treatment, substituting insertion.

20. Drug Delivery Microneedles

21. Biomedical…

22. Drug Delivery Platforms

23. MEMS Microblades
Here is the system layout of Prof Goodson’s project. We can see that the whole system was on one chip and there are several important components like the macro scale heat exchanger system. They are Micro channels in the evaporator region which sits on the chip, heat source; Condenser region and electrokinetic pump providing the driving force of the fluidic medium. Let’s talk about the EK pump first. EK pump controls flow by electrical potential across a porous medium, which generates a force that induces the liquid to flow. The electroosmotic flow (EOF) is generated in the charge double layer that forms in the first few nanometers of the liquid/dielectric interface. Solvated ions move under the influence of an applied external field, carrying the bulk liquid by viscous drag. The electroosmotically-driven flow rate, QEOF, is directly proportional to the applied voltage and the zeta potential of the porous pump medium. The maximum pressure generated, PMAX, is inversely proportional to the square of the pump medium's pore diameter. Therefore, by optimizing the pump medium's pore size and zeta potential, and controlling the applied voltage.
There is a company from Sandia lab research group focus on EK pump application. The animation can help us understand the physical phenomena behind that.

24. Why biochip? - Big bang of bio information

25. What is biochip?
Devices which allow super-high-speed, high-sensitive analysis
of biologically active DNA, Protein, Cells that are
highly integrated on glass, silicon or polymer substrates.

26. Types of biochip
Micro array chip
Biochip
LOC
Bio sensor
Bio

27. DNA chip - functional genomics
Chip which allows to check gene expression or mutation by adhering highly integrated Oligonucleotide, cDNA, genomic DNA, etc. on its substrate

28. Protein chip - proteomics
Chip that has ligands and proteins those can react with specific protein on its surface
Proteins could be segregated, checked and quantitatively analyzed on the chip

29. Cell Chip - functional cellulomics
Detection of physiological signal by real-time reaction of live cells which was impossible by existing methods

30. Lab on a Chip
Micro fab. techniques, Micro/nano fluidics techniques are applied
Dilution, mixing, reaction, separation of sample could be accomplished on a chip

31. Advantages and Applications of LOC

32. Lab-On-A-Chip Applications to Genomics & Proteomics

33. Applications & Vision Chips for research for diagnosis
various platform → various data
gathering data
researcher’s choice by market
for diagnosis
various products → same result
reliability, sensitivity, accuracy are needed
restricted by law and regulations
Most chips were for research so far

34. Roadmap of Bio-chip Technique