Post on 04-Jan-2016
A biochip for recording electrophysiological signals of nematodes
Group 13-27Advisor: Liang DongGroup members:Xuan QiaoYuncong Chen Yang CuiRuiyu Chen
Concept sketch
Biochip device: container as an environment
Electrodes: electrophysiological signal transform
Amplifier: electrophysiological signal measurement
Why C. elegansThe genes of C. elegans nematodes
are similar to those of human beings.
Nematodes are simple, easy to study
Biologists use C. elegans as model system to study toxicology and discover new drugs for human metabolic and degenerative diseases
Why Electrophysiological signals Electrophysiological signals from
C. elegans provide information about the activity of the pharynx (throat) which pumps like a heart during feeding
C. elegans has a distinct set of drug receptors present on its pharynx.
Why biochipLow cost- $30/liter can make a hundred of our devices
High throughput- Once you have the design, it is easy to make hundreds of biochip devices
Simple operation- Biochip devices are easy to use
Testing inveriment1.We don’t have the
optical table to eliminate the influence from movement of people
2. When we do the test in Coover, there is no wire box to enclose the testing area to filter the noise in the air
Testing result
2 pA
1000 m s
2 pA
50 m s
The amplitude shows how strong the nematode is pumping.
The frequency shows how frequent the nematode is pumping.
Initial Contraction
Terminal Contraction
Working process
Pick worm Spin the Biochip
Worms in the bio chip
By using the spinning coder, the biochip can get the worms in every channels. This is why we call it “high trapping rate”
Challenges in The Project
• 15 um channel fabrication
• Gold etching process
• No alignment mark
• Noise reduction
Constraints & Considerations
All equipment and device need to set up on a experiment table.
Group members should wear lab cloth, gloves and goggles.
Gold etching with strong acid
Non-functional requirementsdevice fabricationTaking Picture of Worms and
Taking video
Electrodes fabricationDo alignment with microscope
Division of LaborXuan & Yuncong & Yang: device
design, fabrication and Electrodes fabrication
Abhishek & Ruiyu: amplifier design and construction
Potential RisksAlignment for device and
electrodesChemicals, sharps, UV exposure,
wormsBurning of op-amps, resistors,
capacitorsNoisy signalStrong acid in electrodes
fabricationWorms die in culture
MitigationBeing generally diligent will go a
long wayDuctility: most experienced
member will make device to ensure proper thickness
Safety risks: all trained in lab safety, know proper procedures to avoid accidents
Burned components/noisy signal: use of quality components and careful construction