Indigo Grätzel Cell (DSSC)
Saturday 4th of October

Participants
Collaboration between Hackteria members and Tribe Against the Machine
Lecture performance by Sandra Bühler and Maya Minder member of BadLab project
Badlab project:

Timeschedule
9 am - 9.30am (TWN) 3 am - 3.30 am (ZHR)
Introduction Presentation from Zurich
lecture performance on Indigo: A Chapter into Blue History of Colonialism
9.30 - 10.30 am (TWN) 3.30 am - 4.30 am (ZHR)
indigo dye fermentation introduction
10.30 - 12 am (TWN) 4.30 am - 6 am (ZHR)
BLOCK Indigio textile dying
free work time
12 am - 1 pm (TWN) 6am - 7am (ZHR)
LUNCH BREAK POWER NAPPING
1 pm - 2 pm (TWN) 7am-8am (ZHR)
DIY DSSC making with indigo dyes and berry juice
2 pm - 3 pm (TWN) 8am - 9am (ZHR)
check the converting rate and make it sound
3 pm - 5 pm (TWN) 9am - 11am (ZHR)
free work time
8 pm - 9 pm (TWN) 2 pm - 3 pm (ZHR)
final presentation by all participants
discussion round

關於天然染料靛藍的演講表演
本線上工作坊的第一個部分是對靛藍商品歷史的一次演講表演，這種看法是通過生態女權主義的觀點引發的，我們想挖掘出後殖民主義，以探究歐洲垂死技術歷史的隱藏痕跡。在發明化學合成染色技術之前，在紡織品上使用深色光澤代表著財富、知識和力量。從印度、非洲和中國自然傳播的靛藍植物（Indigofera tinctoria）曾經在歐洲半球有一種對應物，被稱為德國靛藍，也被稱為dyed woad或菘藍（Isatis tinctoria）並且具有悠久的歷史。兩種植物都帶有「印度糖」的化合物，該化合物通過酶作用將氧化還原氧化成靛藍染料。用天然方式生產著色劑是複雜的，而隱藏的歷史則主要關於財富貿易和前現代全球糾纏的故事。直到今天，藍色仍然是基督教徒對瑪莉亞母親長袍顏色的描述，象徵著沉穩、清晰和距離。在中世紀，以某種方式生產這種著色劑是一個複雜的過程，並成為世界許多文化中一種受到嚴格保護的行會技術：像是日本的Shibori、德國的Blaudruck、法國的Denim、斯洛伐克的「Modrotlač」或匈牙利的「Kékfestés」。

隨著商人開始通過英國東印度貿易公司從印度進口更強效的靛藍植物（Indigofera tinctoria），對靛藍顏色的高度需求正在改變全球貿易規則。 當德國人呼籲開始使用印度靛藍顏色時，靛藍戰爭一直持續到公元17世紀，最終為真正的靛藍贏得了戰鬥。 中世紀的歐洲靛藍生產注定要減少，當地和傳統知識也丟失了。 今天，我們依賴於以石油化工為基礎的靛藍的綜合生產。 靛藍植物和顏色的貿易和路線顯示了權力的黑暗歷史和關於地方傳統的戰爭對全球工業生產的後殖民糾纏的痕跡，這些痕跡觸及了與靛藍和牛仔褲生產相關的棉花貿易奴隸制的黑暗歷史。

德語用語「blau machen」，意思是逃離工作或學校並度過閒暇時光。我們發現它某種程度上借鑒了中世紀染藍紡織品的工藝，即「Blaufärben」的工藝。藍色是有毒的，需要化學過程才能首先啟動還原染料浴。我們發現，在中世紀，這與在社區中喝啤酒的慶典活動有關，因為它需要大量的小便來建藍染缸。我們以此為出發點，將歷史敘述化為投機性故事，一個探索拋開了時間的節點，而在黑暗中的中世紀，貿易和文化交流的全球精神、生態相互聯繫也引發了生態女性主義者的觀點。

我們研討會的第二部分是在DIY方法中引入染料合成太陽能電池，以推測使用實施染料合成太陽能電池的技術在未來電子紡織品中的作用。染料敏化太陽能電池（DSSC、DSC、DYSC或Grätzel電池）是屬於薄膜太陽能電池的低成本太陽能電池。它基於在光敏陽極和電解質之間形成的半導體，即光電化學系統。現代版本的染料太陽能電池，也稱為Grätzel電池，最初由加州大學伯克利分校的布萊恩．歐瑞岡（Brian O'Regan）和麥克．格雷策（Michael Grätzel）於 1988 年共同發明，他們後來於1991 年在瑞士洛桑的聯邦理工學院(EPFL) 發布了第一個高效的染敏太陽能電池。麥克．格雷策因這項發明獲得了 2010 年千年技術獎。所有太陽能電池技術的靈感來自大自然通過光合作用將太陽轉化為能量的能力。

Lecture Performance on Natural Dye Indigo
Part of this online workshop was an lecture performance into the commodity history of indigo blue approached to ecofeminist views threw the postcolonial we want to dig into hidden traces of history of european dying technics. Before the invention of synthetic colors the run on deep shiny colors in textile was a fortune of wealth, knowledge and power. The Plant indigo (Indigofera tinctoria) which is naturally spread threw India, Africa and China had a counterpart of plant in the European hemispheres. Also known as the German Indigo it is named dyers woad or glastum (Isatis tinctoria) and has a rich history. Both plants carry the chemical compound of glycose indican that turns enzymatically threw a redox-oxidation into indigo dye. As complex it is to produce the colorant naturally, as hidden its history that relied mostly on merchants stories of wealth, trade and pre-modern global entanglements. The color blue until today is relied in christian depictions to the color of Mother Mary's gown and symbolizes calm, clarity and distance. Somehow in medieval times it was a complex process to produce this colorant and became a well guarded guilds technic in many cultures around the world: Shibori in Japan, Blaudruck in Germany, Denim from France, Modrotlač in Slovakia, or Kékfestés in Hungaria.

The highly demand on indigo color was changing global trade rules as merchants started to import the more potent indigo plant (Indigofera tinctoria) from India through the British East India Trade Company https://en.wikipedia.org/wiki/East_India_Company. While the Germans called out an embarkment on Indian Indigo colors the war on indigo continued until the 17th Ce were finally the battle won for the true Indigo. The medieval european indigo production was doomed to decrease and the local and traditional knowledge got lost. Today we are dependent on the synthetical production of Indigo based on petrol chemical industry. The trade and routes of Indigo plant and color shows traces of postcolonial entanglements of a dark history of power and war about local tradition into global industrial production reaching out strings into the dark history of slavery of cotton trade linked to indigo and denim jeans production.

The german term blau machen, meaning to skip work or school and take leisure time. We found out it somehow takes a reference to the medieval technic of dying textiles blue, the process of Blaufärben. Blue coloring was toxic and needed a chemical process to firstly initiate the vat dye bath. We found out that in medieval times this was connected to a celebration of drinkin beer in a community, since it needed lots of pee to create the vat dye bath. We took this as a starting point to render historical narration into a speculative story telling, a quest threw nodes of time and global, spiritual, ecological corelation of trade and cultural exchange in the dark hidden medieval times threw a Ecofeminists point of view.

Lecture performance (video part)

The second part of our workshop was inducting the dye synthesized solar cell in DIY approach to speculate into role of technics in future e-textiles using implimented dye synthesized solar cells. A dye-sensitized solar cell (DSSC, DSC, DYSC or Grätzel cell) is a low-cost solar cell belonging to the group of thin film solar cells. It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, a photoelectro-chemical system. The modern version of a dye solar cell, also known as the Grätzel cell, was originally co-invented in 1988 by Brian O'Regan and Michael Grätzel at UC Berkeley and this work was later developed by the aforementioned scientists at the École Polytechnique Fédérale de Lausanne, Swiss (EPFL) until the publication of the first high efficiency DSSC in 1991. Michael Grätzel has been awarded the 2010 Millennium Technology Prize for this invention. All Solar Cell Technic is inspired by nature's ability of transforming sun into energy by photosynthesis.

Materials
ITO Glass (2 per cell) the smaller the better it works (1cm-2,5cm)
Iodide solution
Multimeter
aligator clips
adhesie tape
2 clips binder
Alcohol and Distilled water to clean
Pencile
Destined water
Isopropanol
Pipette
Tweezer
small plastic cups for working
Titanium Dioxid (power, 1g)
Acrylic emulsion (little to mix into the Titanium Dioxid)
—> create a thick paste

Indigo color:
60 ml Wasser
3ml sodium hydroxide solution 30%
3g NAtriumdithionit (Na2S2O4)
Indigo Powder
—> mixe all in 40 degree, let sit for 30min

Manual How to
You need two conductive glasses (ITO), take one and put conductive tape on the in square shape to create an empty square, make sure to use the conductive side of the glass. spill the thik paste on the glass and spread it onto the the surface in a thin layer, let it dry for 2 min. Put the glass (takeoff the tape first) on a cooker to heat up on 60 degrees during 10-20min for hardening the Titanium Dioxid paste. take off and let it cool down.

Dive the plate with the titanium dioxide into the indigo color and let sit for 30sec-1min. Take it out and clean it off with droplets of destilled water, repeat with isopropanol (this helps to let it dry out faster) Take the other conductive glass and draw a thin layer of pencil strokes on it, push hard. Or use a candle and create a thin layer of carbon black on top of the conductive surface.

Put the two glasses in sandwich layer on top of each other. Let free some glass on both sides and fix it with two clip binder. Put dropplets of Iodine solution on the edge of each side, so the liquid can fluid in between the two glasses. Attach on each side (only one layer of glass) the aligatorclips with the multimeter. Now you can mesure the electricity with your digital multimeter (put on step 200mV). Firstly you will see how a high number around 260mV will occur and it will drop down. Then wait for about 5 min and try out with the sunlight/torch how the voltage is changing according to the light exposure.

Parameters to play around

• try out your own protocols by using charcoal powder and acrylic emulsion to mix into the titanium dioxide
• try out different naturla dyes to stain: blueberry, raspberry, butterfly pea tea, chlorophylle
• using different temperatures and durations to heat up the titanium dioxide paste
• take alternative materials: try to replace the glass with transparent conductive bioplastic, paper, kombucha
• Drink beer or butterfly pea tea while doing --> "blau machen" means take time off, take a break.

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At the mean time in Taiwan

In addition to indigo dye, we also tried different natural dyes including persimmon dye, shulang dye.

The first row from left to right: indigo dye from tank built in 2019 Jan 21th, indigo dye from tank built in 2019 June 7th, indigo sludge, indigo sludge.
The second row from left to right: 8 years old persimmon juice, 8 years old persimmon juice, 10 years old perssimmon juice, shulang juice.

TiO2 coating on ITO glass

at first we bake it with home baker but the temperature is not high enough to evaporate the solvent mixed in TiO2 (therefore the TiO2 electrode still looks orange)

after some taiwanese bbq style the TiO2 eletrode turned white again (all solvents are evaporate).

Document by Hsiao Ling
以下是來自偉林老師和蕭老師針對藍染歷史的回應，
台灣不算是藍染的殖民史，比起「殖民」，荷蘭當時應該算是「據台」。因為藍染本來就是漢民族擁有的工藝，因此更精確應該說是「移民史」。
荷蘭人一開始來到台灣之後，帶了印度的藍草過來，找福建當地的一些藍染專家來到台灣協助栽種，但一直都種植失敗。直到鄭成功來台，'明末清初的時候，在三峽那個地方才種植成功，把山藍從福建帶過來，目前台灣做藍染的原料主要還是使用山藍跟木藍。
木藍在台灣曾經消失很久，源頭不太確定，但荷蘭應該有留下一些種子，民國84才找到種子復育，在霧峰的農業試驗所種植之後，一位工藝中心的馬老師很積極教大家種植、收草、打靛。學員會帶種子回去試種，才慢慢復育起來，當時累積了一百二十公斤的染料才開始課程，偉林老師跟蕭老師都是當時第一批學員。現在中部以南都有種植木藍。
但在化學染料進來之後嚴重影響到市場需求，因為經濟收入不夠好，木藍種植環境與稻米相似，大家改種米和甘蔗、而山藍與種茶葉的環境相似，且經濟價值較高，所以許多農夫選擇種茶。
Here's the response from Winlin and Ms Hsiao about the indigo dyeing history.
Instead of calling it the history of colonization on indigo dyeing in Taiwan, it's more precise to say the history of immigration, as most of the materials and techniques originally come from Hokkian, China. It's a traditional craft of Han Chinese. It's also controvesial to say the Dutch people "colonized" Taiwan as they only "occupied" part of Taiwan.
When the Dutch people came to Taiwan, they brought Indigo from India and some professionals from Hokkian, trying to develop indigo dyeing industry in Taiwan, but they failed. Until the Zheng Chenggong period (the beginning of Qing Dynasty), Han people brought Strobilanthes Cusia to Taiwan, they successfully grew it in Sanxia, an area famous for indigo dyeing nowadays. Till today Strobilanthes cusia is still one of the main species Taiwanese people use for indigo dyes.
Another specie of indigo material is called Indigofera tinctoria, which disappeared in Taiwan for a long time and was found and revived in 1995 by Miss Ma, an Indigo dyeing professional, who afterwards host workshops for reviving the indigo dyeing using seeds of Indigofera tinctoria in NTCRI. Winlin and Ms Hsiao were part of the team. And nowadays you can find the specie in middle and south part of Taiwan.
We are not sure about the origin of Indigofera tinctoria. It could be the one imported from India by the Dutch people. For now it is mainly grown in the middle and south part of Taiwan.
The import of chemical dyes did give an impact on natural dyeing industry. The farmers would rather grew rice and sugarcane than the Indigofera tinctoria, and grow tea instead of Strobilanthes cusia, as the economic value of rice, sugar and tea is much higher than the indigo materials. (edited)

REFERENCES
Fabrication of dye-sensitized solar cell using natural dyes extracted from Brazilian plants
Grätzel-Cell (Wikipedia) = DSSC
Wikipedia about the Inventior Prof. Dr. M. Grätzel --> he might will win a Nobelprize, teaching in Lausanne, CH
Explenation video: what happenes inside the DSSC-Zell on molecular level
Prof. Dr. M. Grätzel and his invention (German)
Making a Solar Cell From Toothpaste!
傳統藍染技法應用於天然纖維染色之研究
異質地方
Foucault, the Other Spaces, and Human Behaviour
Scientific Papers
Influence of the counter electrode on the photovoltaic performance of dye-sensitized solar cells using a disulfide/thiolate redox electrolyte, by Julian Burschka,a Vincent Brault,b Shahzada Ahmad,ac Livain Breau,b Mohammad K. Nazeeruddin,a Benoît Marsan, Shaik M. Zakeeruddin and Michael Grätzel.
https://pubs.rsc.org/en/content/articlelanding/2012/ee/c2ee03005e/unauth#!divAbstract