Team:UC Davis/Potentiostat Design Inspiration Iteration

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Our biosensor required a potentiostat. A potentiostat is an instrument capable of maintaining a voltage bias between electrodes. <br><br>The bias encourages diffusion but more importantly the transfer of electrons which are recorded, and ultimately related to the species present in solution. We were faced with the decision to buy or build. <br><br>Unfortunately, there weren't any entry-level potentiostats that met our requirements, and commcercial potentiostats are in the thousands of dollars. We needed a cheaper solution if we wanted our device to be consumer friendly. We researched the literature for potentiostat circuits and were presented with the CheapStat.
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Development began on the protoboard. Circuit designs were prepared using the CheapStat as a reference. SMD-ICs were soldered to DIP adapters and the potentiostat was wired for the first time. The protoboard became the primary device with which to develop the software. The protoboard was not designed with a switch to control current ranges, it did include noise however. Fast Fourier transform of the recorded signal showed that the largest component was from the 60 Hz range. Extensive testing showed that the noise was related to the protoboard itself as the signal persisted long after components were deteced. There was no other option but to continue the development by creating a printed circuit board. <img src="https://static.igem.org/mediawiki/2014/3/32/UCDavis_LessThanDesirable.png " height="250px"/>
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Revision as of 07:57, 14 October 2014

UC Davis iGEM 2014

Inspiration & Iteration

Inspiration & Iteration

Get Started!

Getting Started

Inspiration and Iteration

The CheapStat is a budget friendly device developed at UC Santa Barbara several years ago. We aspired to build this circuit and modify the software for our purposes, however, the microcontroller on the CheapStat was controlled predominantly in machine level code. The learning curve seemed unreasonable considering our deadline, so we had to find another solution.

We were ultimately forced to build our own. With a clean slate, we wanted to create a device that would fulfill our needs, but also be welcomed by the iGEM community. We aimed to match the performance of the CheapStat, but also improve in three ways: increase the effective range of the instrument, decrease the cost of the circuit, and convert to an arduino-friendly microcontroller. In this capacity, we have succeeded.

We modeled our circuit after the CheapStat, eventually including more than 30 components. We went on to create five iterative prototypes. Ab abstract outline of the final circuit is pictured below:

Breadboard

Development began on the protoboard. Circuit designs were prepared using the CheapStat as a reference. SMD-ICs were soldered to DIP adapters and the potentiostat was wired for the first time. The protoboard became the primary device with which to develop the software. The protoboard was not designed with a switch to control current ranges, it did include noise however. Fast Fourier transform of the recorded signal showed that the largest component was from the 60 Hz range. Extensive testing showed that the noise was related to the protoboard itself as the signal persisted long after components were deteced. There was no other option but to continue the development by creating a printed circuit board.

Version 1.0

Our biosensor required a potentiostat. A potentiostat is an instrument capable of maintaining a voltage bias between electrodes.

The bias encourages diffusion but more importantly the transfer of electrons which are recorded, and ultimately related to the species present in solution. We were faced with the decision to buy or build.

Unfortunately, there weren't any entry-level potentiostats that met our requirements, and commcercial potentiostats are in the thousands of dollars. We needed a cheaper solution if we wanted our device to be consumer friendly. We researched the literature for potentiostat circuits and were presented with the CheapStat.

Version 1.1

Our biosensor required a potentiostat. A potentiostat is an instrument capable of maintaining a voltage bias between electrodes.

The bias encourages diffusion but more importantly the transfer of electrons which are recorded, and ultimately related to the species present in solution. We were faced with the decision to buy or build.

Unfortunately, there weren't any entry-level potentiostats that met our requirements, and commcercial potentiostats are in the thousands of dollars. We needed a cheaper solution if we wanted our device to be consumer friendly. We researched the literature for potentiostat circuits and were presented with the CheapStat.

Version 1.2

Our biosensor required a potentiostat. A potentiostat is an instrument capable of maintaining a voltage bias between electrodes.

The bias encourages diffusion but more importantly the transfer of electrons which are recorded, and ultimately related to the species present in solution. We were faced with the decision to buy or build.

Unfortunately, there weren't any entry-level potentiostats that met our requirements, and commcercial potentiostats are in the thousands of dollars. We needed a cheaper solution if we wanted our device to be consumer friendly. We researched the literature for potentiostat circuits and were presented with the CheapStat.

Version 1.3

Our biosensor required a potentiostat. A potentiostat is an instrument capable of maintaining a voltage bias between electrodes.

The bias encourages diffusion but more importantly the transfer of electrons which are recorded, and ultimately related to the species present in solution. We were faced with the decision to buy or build.

Unfortunately, there weren't any entry-level potentiostats that met our requirements, and commcercial potentiostats are in the thousands of dollars. We needed a cheaper solution if we wanted our device to be consumer friendly. We researched the literature for potentiostat circuits and were presented with the CheapStat.

Version 1.4

Our biosensor required a potentiostat. A potentiostat is an instrument capable of maintaining a voltage bias between electrodes.

The bias encourages diffusion but more importantly the transfer of electrons which are recorded, and ultimately related to the species present in solution. We were faced with the decision to buy or build.

Unfortunately, there weren't any entry-level potentiostats that met our requirements, and commcercial potentiostats are in the thousands of dollars. We needed a cheaper solution if we wanted our device to be consumer friendly. We researched the literature for potentiostat circuits and were presented with the CheapStat.

Version 2.0

Our biosensor required a potentiostat. A potentiostat is an instrument capable of maintaining a voltage bias between electrodes.

The bias encourages diffusion but more importantly the transfer of electrons which are recorded, and ultimately related to the species present in solution. We were faced with the decision to buy or build.

Unfortunately, there weren't any entry-level potentiostats that met our requirements, and commcercial potentiostats are in the thousands of dollars. We needed a cheaper solution if we wanted our device to be consumer friendly. We researched the literature for potentiostat circuits and were presented with the CheapStat.