NATIONAL INSTITUTE OF TECHNOLOGY, SILCHAR

BIOMEMSSTATE-OF-THE-ART DETECTION

JOHNSON TAYE 11-24-104

MICROELECTRONICS AND VLSI DESIGN DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING

Mentor: PROF. S. BAISHYA

INTRODUCTIONBiomedical Micro Electro Mechanical Systems

i.e. biomedical or biological applications of MEMS.In general, BioMEMS can be defined as:

‘‘devices or systems, constructed using techniques inspired from micro/nano-scale fabrication, that are used for processing, delivery, manipulation, analysis, or construction of biological and chemical entities’’.

Encompass all interfaces of the life sciences and biomedical disciplines with micro- and nanoscale systems.

Dimensions from ~100nm to 200 µm

ADVANTAGES

Sensor element scaled to size of target species, hence providing higher sensitivity

Reduced reagent volumes and associated costs

Reduced time to result due to small volumes resulting in higher effective concentrations

Miniaturization of system and portabilityPoint-of-care diagnosticsMulti-agent detection capabilityPotential for use in vivo as well as in

vitro

BIOMEMS DIAGNOSTICS

BIOSENSORS: “Analytical devices that combine a biologically

sensitive element with a physical or chemical transducer to selectively and quantitatively detect the presence of specific compounds in a given external environment”

COMPONENTS:Sensitive biological element (biological material:

tissue, micro-organisms, organelles, cell receptors, enzymes, antibodies, nucleic acids etc )

Transducer in betweenDetector element

DETECTION METHODS

Many detection methodsKey methods(state-of-the-art):

MechanicalElectricaloptical

DETECTION MODALITIES

Key detection modalities used in BioMEMS and biochip sensors

BIOMEMS & MECHANICAL DETECTION Detection for biochemical entities and

reactionsMicro- and nano- scale cantilever sensors

and chipTwo modes:

Stress sensingMass sensing

MECHANICAL DETECTION(contd.)

Stress sensor:incorporates biological molecules as part of its function.constructed with a specific probe surface layer used to detect a variety of analytes such as DNA, proteins, and antigens.In the detection of analytes such as a specific antigen, the antigen attaches to the probe molecules on the surface of the Microcantilever.collection of the specific analyte on the cantilever surface induces surface stress causing the cantilever to bend

BIOMEMS AND ELECTRICAL DETECTION 3 Basic types of Electrochemical Biosensors:

Amperometricinvolves the electric current associated with the

electrons involved in redox processesPotentiometric

Measure a change in potential at electrodes due to ions or chemical reactions at an electrode e.g. ISFET

Conductometricmeasure conductance changes associated with

changes in the overall ionic medium between the two electrodes

BIOMEMS AND OPTICAL DETECTION

Based on fluorescence or chemiluminescence

LAB-ON-A-CHIP

Is a term for devices that integrate (multiple) laboratory functions on a single chip of only millimeters to a few square centimeters in size.

Capable of handling extremely small fluid volumes down to less than Pico liters (Microfluidics).

Lab-on-a-chip devices are a subset of MEMS devices and often indicated by "Micro Total Analysis Systems" (µTAS) as well.

LAB-ON-A-CHIP

CONCLUSION AND FUTURE DIRECTIONSConsiderable progress has been made in the field

of BioMEMS with research areas merging into nanobiotechnology.

BioMEMS also enable us to probe, measure, and explore the nano-machinery in the biological world such as single cells.

Future research:Integrating diagnostic with therapeutic devices and

personalized medicineBioMEMS for hybrid devices and 3-D artificial organsBioMEMS for novel tools in nanobiologyQuantum dots for cancer treatmentNano robots for surgery(use of microgrippers)

REFERENCESBioMEMS: state-of-the-art in detection,

opportunities and prospects, by Rashid Bashir. BioMEMS Overview Learning Module, Southwest

Center for Microsystems Education (SCME), University of New Mexico.

Bio-MEMS Technologies and Applications, Edited by Wanjun Wang and Steven A. Soper, CRC Press, Taylor and Francis Group.

Disposable Smart Lab on a Chip for Point-of-Care Clinical Diagnostics invited paper Chong H. Ahn, Jin-Woo Choi, Gregory Beaucage, Joseph H. Nevin, member, IEEE, Jeong-Bong Lee, Aniruddha Puntambekar, and Jae Y. Lee.