IEC 63203-301-1:2024

IEC 63203-301-1 ®
Edition 1.0 2024-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Wearable electronic devices and technologies –
Part 301-1: Test method of electrochromic films for wearable equipment

Technologies et dispositifs électroniques prêts-à-porter –
Partie 301-1: Méthode d’essai des films électrochromes pour les équipements
prêts-à-porter
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IEC 63203-301-1 ®
Edition 1.0 2024-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Wearable electronic devices and technologies –

Part 301-1: Test method of electrochromic films for wearable equipment

Technologies et dispositifs électroniques prêts-à-porter –

Partie 301-1: Méthode d’essai des films électrochromes pour les équipements

prêts-à-porter
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 59.080.80  ISBN 978-2-8322-8461-2

– 2 – IEC 63203-301-1:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test method of electrochromic films for wearable equipment . 6
4.1 Overview. 6
4.2 Equipment and tools . 7
4.3 Test procedure . 7
4.4 Measurement and data analysis . 8
4.5 Test report . 10
Annex A (informative) Transmittance measurement guidance . 11
Bibliography . 12

Figure 1 – Schematic diagram of the electrochromic films: bleached and darkening . 6
Figure 2 – Schematic figure of the test equipment and tools . 7
Figure 3 – Bleaching and darkening transition time of the electrochromic optical
element. 9
Figure A.1 – Characteristics of the transmittance change of the electrochromic optical
shutter element . 11

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WEARABLE ELECTRONIC DEVICES AND TECHNOLOGIES –

Part 301-1: Test method of electrochromic films for wearable equipment

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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shall not be held responsible for identifying any or all such patent rights.
IEC 63203-301-1 has been prepared by IEC technical committee 124: Wearable electronic
devices and technologies. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
124/263/FDIS 124/273/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

– 4 – IEC 63203-301-1:2024 © IEC 2024
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 63203 series, published under the general title Wearable electronic
devices and technologies, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
WEARABLE ELECTRONIC DEVICES AND TECHNOLOGIES –

Part 301-1: Test method of electrochromic films for wearable equipment

1 Scope
This part of IEC 63203-301-1 specifies procedures and definitions for the test method of
electrochromic films for wearable equipment. This document deals with the colour changing
range in visible light and the electrochromic properties of transmittance, response time and
evaluation method of long-term stability. This document excludes applications of electrochromic
films to displays.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-1, Environmental testing – Part 1: General and guidance
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
transmittance
ratio of transmitted power to incident power for given conditions of spectral composition,
polarization and geometrical distribution
Note 1 to entry: In optics, frequently expressed as transmittance density or as a percentage. In communication
applications, generally expressed in decibels.
[SOURCE: IEC 60050-731:1991, 731-03-31]
3.2
response time
time from a sudden change of a control quantity until the corresponding change of an output
quantity has reached a specified fraction of its final value
[SOURCE: IEC 60050-431:1980, 431-02-12]
3.3
darkening time
time when a control quality suddenly becomes saturated until the corresponding change of an
output quantity has reached a dark stage of its final value

– 6 – IEC 63203-301-1:2024 © IEC 2024
3.4
bleaching time
time from a sudden change of a control quantity until such time as the corresponding change
of an output quantity has reached a bright stage of its final value
3.5
long-term stability
property of the electrochromic system which implies that for a sufficiently small initial
displacement from the rest position or for a sufficiently small disturbance the state variables
remain within a sufficiently small neighbourhood of the rest position in the long term
4 Test method of electrochromic films for wearable equipment
4.1 Overview
+ + + +
The electrochromic films have such characteristics that as the ions of H or Li (H or Li is
given by way of example) are injected or released by application of an electric field the films
change colour. Figure 1 shows the two statuses of electrochromic film. The electrochromic film
consists of a pair of the electrochromic layers on the transparent electrode which can be applied
to the external electric field. As the external electric field is applied on the transparent
electrodes, the internal electrical potential of electrochromic layers has been changed. The
changed potential affects the transmittance of the electrochromic layers.
In order to use the electrochromic films, the transmittance change, the response time, and the
long-term stability for colour changing of the devices should be measured. The test procedure
of the properties is described in 4.3.

Key
1 working electrode
2 counter electrode
3 electrolyte
Figure 1 – Schematic diagram of the electrochromic films: bleached and darkening

4.2 Equipment and tools
In order to test the device under test, a voltage generator (DC power supply), a sample stage,
a spectrometer, a computer and an optical measurement system shall be used to evaluate the
electrochromic optical shutter element. The voltage generator shall generate a constant voltage
level during the measurement and should also be controlled by 0,1 V step-wise voltage change.
The wavelength for measurement should be changed from 380 nm to 750 nm. The detector
should collect the light which is transmitted through electrochromic film.

Key
1 power meter
2 detector
3 electrochromic film
4 light source
5 potentiostat
Figure 2 – Schematic figure of the test equipment and tools
In Figure 2 the electrochromic film which is to be evaluated is located between the light source
and the detector. The light source can change the wavelength from 380 nm to 750 nm and the
detector can collect the transmitting light intensity using a photodetector showing the signal
level on the power meter. The transmittance of the electrochromic film can be changed with the
applied field generated by the potentiostat.
4.3 Test procedure
The detailed test procedures are described below. The test environment shall be in accordance
with IEC 60068-1, with a temperature of 25 °C ± 2 °C and a humidity of 50 % ± 2 %, under
300 lux. The percentage of transmittance is calculated by the ratio of the radiance in wavelength
transmitted by that surface over the radiance received by that surface, as shown in Formula (1).
φ
t
τT% × 100
( ) (1)
φ
m
where
τ is the transmittance;
φ is the radiance in wavelength transmitted; and
t
φ is the radiance received by that surface.
m
=
– 8 – IEC 63203-301-1:2024 © IEC 2024
1) Turn on the light source and stabilize the lamp (for more than 10 min).
2) Perform the transmittance calibration without the sample. The transmittance calibration is
based on a transmittance of 0 % when the shutter of the light source is closed, and a
transmittance of 100 % when the shutter of the light source is open.
3) Attach an electrochromic film to the sample stage.
4) Set the output voltage from the bleaching voltage to the darkening voltage by 0,1 V for a
period of 10 s and duty of 50 % using the function generator and power meter.
5) Apply the power to the electrochromic film to drive the maximum bleached transmittance,
and then change the driving voltage to the minimum darkened transmittance, which makes
one cycle (continue for 20 cycles).
6) Measure the spectral transmittance in the visible range (380 nm to 750 nm) while the
voltage applied (for more than 10 cycles).
7) From the results measured in step 6), the transmittance value in the darkened state is
evaluated.
8) From the results measured in step 6), the transmittance value in the bleached state is
evaluated.
9) Calculate the response time from the measured results. The darkened change time is the
time required for 90 % of the range of transmittance change in step 8).
10) To measure the long-term stability, the procedure of steps 4) to 9) should be repeated for
10 000 cycles including step 5) and step 6). The number of repetitions may be decided by
agreement between the user and the supplier.
4.4 Measurement and data analysis
For the transmittance discoloration time of the electrochromic optical shutter element, Figure 3
a) and Figure 3 b) show the bleaching time and darkening time of the electrochromic optical
shutter device, respectively. The discoloration time was defined as the time required for 90 %
and the darkening
transmission transition. As shown in Figure 3, the bleaching time was r
b,90
time was r . See Annex A for guidance on transmittance measurement.
d,90
In Figure 3 a), the auxiliary vertical lines show the response time for bleaching. The top line of
the three auxiliary horizontal lines shows the maximum transmittance of the film and the bottom
line is for the minimum transmittance of the film. The bleaching process starts from the time of
r to the 90 % finished mark at r . The transmittance changes from t to t and the
b,s b,e b,s b,90
maximum bleached states shows the maximum transmittance of t . The range of the
b,e
transmittance change for bleaching is calculated by subtraction from t of t . The middle
b,90 b,s
line of the three auxiliary horizontal lines shows the 90 % mark of the range of transmittance
change.
In Figure 3 b), the auxiliary vertical lines show the response time for darkening. The bottom line
of the three auxiliary horizontal lines shows the minimum transmittance of the film and the top
line is for the maximum transmittance of the film. The darkening process starts from the time of
r to the 90 % finished mark at r . The transmittance changes from t to t and the
d,s d,e d,s d,90
maximum darkened states shows the minimum transmittance of t . The range of the
d,e
transmittance change for darkening is also calculated by subtraction of the minimum
transmittance from the maximum transmittance. The middle line of the three auxiliary horizontal
lines shows the 90 % mark of the range of transmittance change for darkening.

a) Bleaching transition time of the electrochromic optical shutter element

b) Darkening transition time of the electrochromic optical shutter element
Key
r bleaching start time r darkening start time
b,s d,s
r bleaching finish time r darkening finish time
b,e d,e
r bleaching transition time (90 % bleached) r darkening transition time (90 % bleached)
b,90 d,90
t minimum bleached transmittance t maximum darkened transmittance
b,s d,s
t maximum bleached transmittance t minimum darkened transmittance
b, d,e
t transmittance of 90 % bleached t transmittance of 90 % darkened
b,90 d,90
NOTE The transmittance can be measured in 380 nm to 750 nm wavelength.
Figure 3 – Bleaching and darkening transition time of
the electrochromic optical element

– 10 – IEC 63203-301-1:2024 © IEC 2024
4.5 Test report
The report shall include the following items:
a) description of the testing room specification;
b) date of test;
c) atmospheric conditions of test;
d) the range of the transmittance change;
e) the spectral transmittance with the voltage applying time which is described as the
transmittance value graph with wavelength change. The maximum transmittance of the
sample at 550 nm wavelength is a representative value (bleached status);
f) the spectral transmittance with the voltage applying time which is described as the
transmittance value graph with wavelength change. The minimum transmittance of the
sample at 550 nm wavelength is a representative value (darkened status);
g) the response time until each status transition is completed;
h) for measuring the long-term stability of the electrochromic films, the measurement should
be repeated 10 000 cycles. The transmittance should be recorded every 1 000 times. The
number of repetitions can be decided by agreement between the user and the supplier.
...