Bacteria growth monitoring through an on-chip capacitive sensor

Minimum inhibition concentration (MIC) of antibiotic is an effective value to ascertain the agent and minimum dosage of inhibiting bacterial growth. However, current techniques to determine MIC are labor intensive and time-consuming, and require skilled operator and high initial concentration of bacteria. To simplify the operation and reduce the time of inhibition test, we developed a microfluidic system, containing a concentration generator and sub-micro-liter chambers, for rapid bacterial growth and inhibition test. To improve the mixing effect, a micropillar array in honeycomb-structure channels is designed, so the steady concentration gradient of amoxicillin can be generated. The flanged chambers are used to culture bacteria under the condition of continuous flow and the medium of chambers is refreshed constantly, which could supply the sufficient nutrient for bacteria growth and take away the metabolite. Based on the microfluidic platform, the bacterial growth with antibiotic inhibition on chip can be quantitatively measured and MIC can be obtained within six hours using low initial concentration of bacteria. Overall, this microfluidic platform has the potential to provide rapidness and effectiveness to screen bacteria and determine MIC of corresponding antibiotics in clinical therapies.

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Multichannel 65 zF rms Resolution CMOS Monolithic Capacitive Sensor for Counting Single Micrometer-Sized Airborne Particles on Chip

IEEE Journal of Solid-State Circuits ◽

10.1109/jssc.2016.2607338 ◽

2016 ◽

Vol 51 (11) ◽

pp. 2545-2553 ◽

Cited By ~ 33

Author(s):

Pietro Ciccarella ◽

Marco Carminati ◽

Marco Sampietro ◽

Giorgio Ferrari

Keyword(s):

Capacitive Sensor ◽

Airborne Particles ◽

On Chip

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CMOS capacitive sensor array for continuous adherent cell growth monitoring

2016 IEEE International Symposium on Circuits and Systems (ISCAS) ◽

10.1109/iscas.2016.7539032 ◽

2016 ◽

Cited By ~ 3

Author(s):

Ghazal Nabovati ◽

Ebrahim Ghafar-Zadeh ◽

Antoine Letourneau ◽

Mohamad Sawan

Keyword(s):

Cell Growth ◽

Sensor Array ◽

Capacitive Sensor ◽

Adherent Cell ◽

Growth Monitoring

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Wide Input Range Supply Voltage Tolerant Capacitive Sensor Readout Using On-Chip Solar Cell

Journal of Circuits System and Computers ◽

10.1142/s0218126616400065 ◽

2015 ◽

Vol 25 (01) ◽

pp. 1640006

Author(s):

Suyan Fan ◽

Man-Kay Law ◽

Mingzhong Li ◽

Zhiyuan Chen ◽

Chio-In Ieong ◽

...

Keyword(s):

Solar Cell ◽

Power Consumption ◽

Supply Voltage ◽

Capacitive Sensor ◽

Cmos Process ◽

Readout Circuit ◽

Worst Case ◽

Average Power Consumption ◽

Input Range ◽

On Chip

In this paper, a wide input range supply voltage tolerant capacitive sensor readout circuit using on-chip solar cell is presented. Based on capacitance controlled oscillators (CCOs) for ultra-low voltage/power consumption, the sensor readout circuit is directly powered by the on-chip solar cell to improve the overall system energy efficiency. An extended sensing range with high sensing accuracy is achieved using a two-step successive approximation register (SAR) and delta-sigma ([Formula: see text]) analog-to-digital (A/D) conversion (ADC) scheme. Digital controls are generated on-chip using a customized sub-threshold digital standard cell library. Systematic error analysis and optimization including the finite switch on-resistance, buffer input-dependent delay, and SAR quantization nonlinearity are also outlined. High power supply rejection ratio (PSRR) is ensured by using a pseudo-differential topology with ratiometric readout. The complete sensing system is implemented using a standard 0.18[Formula: see text][Formula: see text]m complementary metal-oxide-semiconductor (CMOS) process. Simulation results show that the readout circuit achieves a wide input range from 1.5[Formula: see text]pF to 6.5[Formula: see text]pF with a worst case PSRR of 0.5% from 0.3[Formula: see text]V to 0.42[Formula: see text]V (0.67% from 0.3[Formula: see text]V to 0.6[Formula: see text]V). With a 3.5[Formula: see text]pF input capacitance and a 0.3[Formula: see text]V supply, the [Formula: see text] stage achieves a resolution of 7.1-bit (corresponding to a capacitance of 2.2[Formula: see text]fF/LSB) with a conversion frequency of 371[Formula: see text]Hz. With an average power consumption of 40[Formula: see text]nW and a sampling frequency of 47.5[Formula: see text]kHz, a figure-of-merit (FoM) of 0.78[Formula: see text]pJ/conv-step is achieved.

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Charge Based Capacitive Sensor Array for CMOS Based Laboratory-On-Chip Applications

2006 5th IEEE Conference on Sensors ◽

10.1109/icsens.2007.355485 ◽

2006 ◽

Cited By ~ 4

Author(s):

E. Ghafar-Zadeh ◽

M. Sawan

Keyword(s):

Sensor Array ◽

Capacitive Sensor ◽

On Chip

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Ultrasonic transducer kit for bacteria growth monitoring system

2010 6th International Colloquium on Signal Processing & its Applications ◽

10.1109/cspa.2010.5545264 ◽

2010 ◽

Author(s):

H N A Salwa ◽

K Sundaraj ◽

A A Azamimi ◽

M M D Zulkali

Keyword(s):

Monitoring System ◽

Ultrasonic Transducer ◽

Growth Monitoring ◽

Bacteria Growth

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On–Chip Droplets Sensing using Capacitive Technique

Jurnal Teknologi ◽

10.11113/jt.v61.1641 ◽

2013 ◽

Vol 61 (2) ◽

Author(s):

Mohamad Faizal Abdullah ◽

P. L. Leow ◽

M. A. Abd Razak ◽

F. K. Che Harun

Keyword(s):

Low Cost ◽

Microfluidic Channel ◽

High Sensitivity ◽

Microfluidic Devices ◽

Capacitive Sensor ◽

Sample Volume ◽

Microfluidic System ◽

Coplanar Electrodes ◽

On Chip ◽

Significant Attention

Significant attention has been given on the development of droplets–based microfluidic system because of its potential and apparent advantages. Beside the advantages of reducing the sample volume, it’s also offer less time consuming for the analysis. Optical and fluorescence among the famous method that was used in detection of droplets but they are normally bulky, expensive and not easily accessed. This paper proposed a simple, low cost and high sensitivity for droplets sensing in microfluidic devices by using capacitive sensor. Coplanar electrodes are used to form a capacitance through the microfluidic channel. The design of eight pair of electrodes was used to detect the presence of a droplet. Changes in capacitance due to the presence of a droplet in the sensing area is detected and used to trigger the microscope to capture the image of detected droplets in microchannel. The measurement of droplets detected and counting are displayed through a LABVIEW interface in the real time.

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