Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A USB-controlled potentiostat/galvanostat for thin-film battery
  characterization   This paper describes the design of a low-cost USB-controlled
potentiostat/galvanostat which can measure or apply potentials in the range of
+/-8V, and measure or apply currents ranging from nanoamps to max. +/-25 mA.
Precision is excellent thanks to the on-board 20-bit D/A-convertor and 22-bit
A/D-convertors. The dual control modes and its wide potential range make it
especially suitable for battery characterization. As an example use case,
measurements are presented on a lithium-ion test cell using thin-film anatase
TiO2 as the working electrode. A cross-platform Python program may be used to
run electrochemical experiments within an easy-to-use graphical user interface.
Designed with an open hardware philosophy and using open-source tools, all the
details of the project (including the schematic, PCB design, microcontroller
firmware, and host computer software) are freely available, making custom
modifications of the design straightforward.

2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org