1. MEMS.
THE DRIVING FORCE
FOR REVOLUTIONIZING
MODERN DAY MEDICAL
ELECTRONICS.
Presented by: Deepam Sahu.
Roll: 001110701022.
UG 4th Year.
E.T.C.E. Dept.
Jadavpur University.
© memx.com

2. WHAT IS MEMS ?
• Micro-electro-mechanical systems (MEMS) refer to a
collection of micro-sensors and actuators that can sense
its environment and have the ability to react to changes
in that environment with the use of a microcircuit
control.
• They may include integrating antenna structures,
facilitating transmission of command signals into micro-
electro-mechanical structures for desired sensing and
actuating functions. MEMS are made up of components
having dimensions in range of 1- 10 µm. Their overall
dimensions range from 20 µm to 1 mm.
© memx.com

3. BASIC STRUCTURE OF MEMS.
MEMS is fabricated using silicon micromachining techniques which refers to
fashioning microscopic mechanical parts out of silicon substrate or on a
silicon substrate.
A typical MEMS is SIP (System in Package) IC, usually consisting
of two parts.
• The first part is the micro-sensor that collects the data from
the environment.
• The second part is the central unit, responsible for
processing the data, collected by the sensor. In addition,
there may be integrated antenna structures, responsible for
transmitting data and receiving commands for proper
functioning.
© analog.com

4. The micro-sensors in MEMS may be based on different sensing principles;
• Piezoresistive Sensing: Piezoresistive sensing uses the resistors varying with the
external pressing to measure such physical parameters as pressure, force, etc.
• Capacitive Sensing: Capacitive sensing uses the diaphragm deformation–induced
capacitance change to convert the information of pressure, force, etc., into the
electrical signals such as changes of oscillation frequency, charge, and voltages.
• Piezoelectric Sensing: Piezoelectric sensing is based on the piezoelectric effect of
piezoelectric materials. The electrical charge change is generated when a force is
applied across the face of a piezoelectric film.
• Resonant Sensing: Resonant sensing principle is based on the fact that the
resonant frequency of a resonator varies with the strain (stress) generated in the
resonator structure. By picking up the natural frequency variation of the
resonator, the physical information that caused the strain will be sensed.

5. MEMS: REVOLUTIONIZING THE PERSONAL
HEALTHCARE SCENARIO.
Bulky and centralized hospital equipments
now have a new substitute – handheld
personalized healthcare equipments. MEMS is
all set to give healthcare a new definition.
Some typical applications of MEMS in
Healthcare are pedometer, blood pressure
monitors, Glucometers, hearing aids etc.
MEMS can also be used in complex
procedures such as DNA Analysis.

6. APPLICATION OF MEMS IN PEDOMETER.
©Sony Electronics.
The pedometer function is one of the most useful functions
in many of the wearable electronic devices available today.
Almost all the smart bands, emerging nowadays, take help of
MEMS, such as gyroscopes and accelerometers, to measure
the distance and the number of steps.
Most pedometers use a 3-axis accelerometer that senses
motion along three axes: x, y and z. This data is then
processed with the help of the processing unit, to calculate
the number of steps and the distance travelled.

7. As we can see, the peaks in the chart clearly approximate the user’s steps.
Unfortunately, the sensor is far from ideal and produces quite a bit of noise. This
can be verified from the data, collected by the sensor of a device that’s just sitting
on a desk.
As an example, let’s look at the acceleration data from the X-axis generated by
walking:

8. Obviously, the above method is not perfect. The quality of their results will
depend on a number of variables, both well known and less predictable. Even
the device’s position on the user’s person will affect the results.
Each MEMS sensor returns data, measured along all the three orthogonal axes.
Since it doesn’t know in advance the device’s physical orientation, it needs to
process the data from all three axes. The most common method for processing
the results is to find the average of the data of all the three axes. This method
yields decent results as can be seen from the graph below:
acceleration
time

9. BIO-MEMS.
Bio-MEMS is an abbreviation for biomedical (or
biological) micro-electro-mechanical systems. A broad
definition for bio-MEMS can be used to refer to the science
and technology of operating at the micro-scale for biological
and biomedical applications, which may or may not include
any electronic or mechanical functions. Some of its major
applications include genomics, proteomics, molecular
diagnostics, point-of-care diagnostics.
Bio-MEMS may be fabricated on a wide variety of substrates like paper, silicon, glass,
plastic, polymers, biological materials, depending on its compatibility with fabrication
technique as well as point of application.
© ST Microelectronics

10.  Bio-MEMS as Miniaturized Biosensors: Biosensors are devices that consist of a
biological recognition system, called the bio-receptor, and a transducer. The interaction
of the analyte with the bio-receptor causes an effect that the transducer can convert
into a measurement, such as an electrical signal. The most common bio-receptors used
are based on antibody-antigen interactions, enzymatic interactions, cellular
interactions, etc.
 Bio-MEMS for diagnostics: Bio-MEMS have been developed to take saliva, blood, or
urine samples and in an integrated approach, perform sample preconditioning, sample
fractionation, signal amplification, analyte detection, data analysis, and result display.
 Bio-MEMS in tissue engineering: Bio-MEMS have been extensively used in tissue
engineering to provide precise control over the factors that optimize the culture and
growth of cells and tissues.

11. LAB ON A CHIP:
With the advancement of MEMS technology, the
concept of “Lab on a Chip” (LOCs) has become the
backbone of personal healthcare.
• Lab on a Chip(LOC) is a device that integrates one or
several laboratory functions on a single chip of only
millimetres to a few square centimetres in size.
• These devices are usually fabricated using photolithographic techniques, and
consist of separate compartments for collection, manipulation, testing of bodily
fluids.
• The Bio-MEMS in the LOC are responsible for sensing the properties of the fluid
and converting them into corresponding electrical signals to be analysed by the
processing unit. The data collected can then be either displayed or sent to
database with the help of Bluetooth technology.
© ST Microelectronics

12. Advantages of LOCs:
 Low fluid volumes consumption which means less waste, lower reagents
costs and less required sample volumes for diagnostics.
 Faster analysis and response times due to short diffusion distances, fast
heating, high surface to volume ratios and small heat capacities.
 Better process control because of a faster response of the system.
 Compactness of the systems due to integration of much functionality and
small volumes.
 Lower fabrication costs, allowing cost-effective disposable chips, fabricated
in mass production.
The most common examples of LOCs, used in personal healthcare include blood
glucose meters, blood cell count detectors, infectious antigen detectors, etc.
Because of faster response times of LOCs, timely diagnosis of abnormalities in
the human body are possible, thus providing efficient treatment of the
condition.

13. FUTURE ASPECTS:
• MEMS has opened many new avenues for healthcare. MEMS has made it
possible to monitor the patients in real time without admitting them in the
Hospitals.
• With the advancement of connectivity and software, MEMS have also paved
the way for collection, transmission, and processing of health related data of an
individual.
• Depending on the nature of the data collected over a considerable period of
time, it has been possible to diagnose any bodily abnormalities at an early
stage.
• The advancement of semiconductor fabrication industry has played an
important factor in reducing the cost of MEMS. As a result, we can expect more
use of MEMS in providing cost effective treatment to patients, especially for
those residing in developing countries.

14. REFERENCES:
• Medical Electronics design: MEMS in healthcare.
• “Counting Steps with MEMS” by Dmitry Elyuseev.
• “MEMS for Biomedical Application” by Shekhar Bhansali.
• www.interacademies.net.
• www.memx.com.
• www.st.com.
• www.analog.com.
• www.Wikipedia.org.