Silk : An ancient wonder material

  • Silk is a biocompatible biodegradable sustainable protein based fiber with high tensile strength - 70-75% of silk is made of a protein fibroin which is hydrophobic beta sheet blocks, interrupted by small hydrophilic groups and a glue-like protein, sericin, comprising 25-30 % by weight.
  • Widespread usage for biomedical applications - The beta-sheets contribute much to the high mechanical strength of silk fibers, around 740 MPa, which is tens of times that of poly(lactic acid) and hundreds of times that of collagen.
  • Silk Bio Foundries - Industrial Production of Silk based biomaterials - The impressive mechanical strength coupled with its biocompatibility and biodegradability makes silk very competitive for applications in biomaterials. In addition, the properties of silks from various kinds of silkworms vary widely, which provides more choices for their use in tissue engineering.
  • Traditional usage in Fabrics - Typically associated with luxury; fabrics like satin, charmeuse, habutai, chiffon, taffeta, crêpe de chine, dupioni, noil, tussah, and shantung are all based on Silk
  • Transient Electronics - Silk as a base ingredient in biodegradable electronics is lately being discussed in literature

Silk in India

  • India produces four types of silks. They come from distinct species of silkworms which produce silks that differ in their protein sequence and hence also exhibit distinct physical properties.
  • Mulberry silk contributes to majority of silk production while Eri silk is a distant second.
  • Eri, Tasar and Muga are still referred to as Wild Silk since the corresponding silkworms have not been domesticated to the extent of Mulberry Silkworm (Bombyx Mori).

Eri Silk: Our venture is on large scale robust production of Eri or Ahimsa Silk produced by partially domesticated silkworm “Samia Ricini”  native to North East India. Samia Ricini is a polyphagous insect primarily raised on two abundant commercial crops cultivated in India, Castor and Tapoica.
The cotton like texture of the Eri cocoon does not necessitate the pre-mature death of pupae, therefore popularized as – “Ahimsa Silk”. Eri Silk is known to facilitate body temperature regulation allowing its usage in all seasons.

Ironically yet importantly, Ahimsa silk producing Eri Pupae is an important ingredient in many culinary delicacies across  north eastern states of India as well as South east asian countries.

Eri Silk Foundries - More than just Silk

Silk Foundry addresses the current issues of farm waste processing, climate friendly protein production and sustainable and efficient biomaterial production

We are building automated feeding and monitoring system for mass rearing of silkworms

We use farm residue from Castor (Ricinus communis) and Tapioca (Manihot esculenta) plantations to make a semi artificial diet to feed silkworms

The silkworms then make a cocoon and become pupae. The protein rich pupae are consumed in north eastern states of India and neighboring countries of the south-east Asia. The cocoon shells are used to make lustrous Eri silk.

Feeding the human population sustainably

A decade ago, the world consumed around a thousand million metric tons of animal based protein. And in the coming three decades the demand for animal protein is set to reach around 1600 million metric tons. An increase of around 60% [global food outlook 2012 and 2013 by Food and Agriculture Organization (FAO) of the UN]

In 2018 the farm animals consumed around thousand billion tons of compound animal feed worth 400 billion USD. As the demand for animal protein goes up the demand for feed for animal protein is also set to double by 2050 [The International Feed Industry Federation, https://ifif.org/global-feed/statistics/].

Crop residue In India: Problem and an opportunity

  • Crop residue are unused parts of our crops such as leaves and stems
  • India produces huge quantities crop residue every year
  • If not managed properly they can contribute to greenhouse gas emissions via decomposition and in some cases where it is burned can cause serious air pollution.
  • On the other hand the huge quantities of this biomass also presents a great opportunity for upcycling via Silk Foundries

Automation

Automation is the key to the scalability of this venture. Hence we have developed tools and systems for automating every step of the entire process, from farm waste collection to processing the silk. Some examples of these efforts are shown above.
  • Our semi-artificial diet (SAD) reduces one of the major constraint for perennial silkworm rearing.  The rearing could be done anywhere as long as correct environmental constraints are maintained. We are in process of filing a patent application for our novel SAD formulation.
  • We have adopted the open-source Farmbot into a Silkbot and have created a feeder module for our automated feeding system.
  • Silknet is encoder-decoder convolutional neural network  that monitors the growth, movement and health of the silkworms. Silknet is key in early disease monitoring of the larvae. Silknet is available as an open-source tool.