Delving into Best Practices and the Future of Wearable Technology

This chapter will provide information on the steps to take to help find solutions for common errors or issues that can happen when we prototype. We will look at a few handy tips to help us with our wearable journey, as well as understand how to set up our circuits so that they last. We will also have a look at batteries and power solutions.

We will look at troubleshooting and some of the common ways you can take a step-by-step approach to finding the problem. We will finish up with a look at the future and what the world of wearables may hold! What are scientists, technologists, engineers, and designers exploring in these intersections? For example, designers and engineers are creating medical devices worn on the body and collecting essential information for healthcare. We look toward the possible future directions for wearables, on-body systems, and creative circuits. We discuss “What does the future hold...

Technical requirements

This chapter includes new techniques and explores ways to move your circuits from prototypes to even more ambitious projects, so we don’t have a specific requirement list.

Best practices

I hope you’ve had an exciting journey with me from our first steps in learning about electronic circuits to using conductive threads and fabrics and exploring e-textile toolkits. We’ve whizzed by several Arduino systems and explored some of the functions of ESP32-based boards. Throughout all the learning, we also had time for theory, the important consideration of why we want to make wearables, and what was made before us. We looked to a Design Innovation method to help create wearables with purpose. Hopefully, you’re now equipped to bring your wearables to life through recreating that process, from early concept prototyping to making and using your wearable.

This chapter is a place for some of the extras that can help to improve or bring your wearables to the next level or just simplify the process for you – some of which I’ve learned over the years of making and teaching, and all of which I’ve found useful.

Let’...

Additional techniques

The techniques in this section are ways you can make your wearables more durable or construct them in different ways. If a circuit I’m working on is particularly fragile or has very thin wires that could break off from where they are soldered, I like to make it more durable. I use a more permanent solution than what covering ends with fray check or clear nail varnish can accommodate.

Using resin will give a very sturdy bond and covering for your wires. You can buy epoxy resin, which comes in two bottles typically – one is a hardener and when you mix it with the other, they will cure (harden or set) over a specific period of time. This can often be 24 hours. However, many gel nail polish systems are made from a resin, which cures with UV lights in a minute or so. You can be very specific about where you want the resin to go and you don’t need to mix large quantities – you don’t need to mix anything! This can be a great way...

Taking your prototypes further

If you’ve made a prototype on a breadboard and then moved it to a garment, it’s likely you’re testing it. This will help you to iterate it and discover improvements. Once these have been worked through, it might be time for you to move it to a circuit board. A printed circuit board (PCB) is the unique design that you’ve taken to a manufacturer to build according to your custom designs and then you can make unlimited copies. One of the boards I’ve made (see Figure 14.20) has slits in the sides so you can attach it to a strap for attaching to clothing or bags:

Figure 14.20 – A PCB manufactured from my design made in Eagle

The circuit board has the traces, the connections between the components, and you would solder on the actual components. You can also get flexible circuits now, but they cost a lot more than traditional circuit boards. I usually go for the thinnest board they offer so that...

Power considerations

Powering the wearables you make is an important part of the overall circuit. Using a Lithium Polymer (LiPo) battery means that it is rechargeable. We need ones rated at 3.7 V for our projects because the circuit boards we are using are 3.3 V-rated, as shown in Figure 14.22:

Figure 14.22 – Varieties of LiPo batteries

The battery’s capacity is measured in amp hours – you’ll see mAh for milliamp hours on the LiPo batteries that we use for wearables. We can use a capacity in the range of 150 to 2000 mAh for our projects. They will be flat and different rectangular shapes. They typically have a foil-type case and don’t weigh a lot, which makes them good for wearable designs. It can be a good idea to provide information for the wearer to know how much charge is left. You can buy a battery capacity indicator (see Figure 14.23) that you can integrate with your circuit:

Figure 14.23 – A battery capacity...

How to troubleshoot

Sometimes, things go wrong when we are connecting our circuit hardware or programming it. As we’ve worked through the exercises, I’ve noted some things you can try to help with issues. I usually turn to forums to see whether someone has had a similar problem or issue to what I am experiencing. You’ll find that this is one of the really positive things about using the boards we’ve chosen throughout the book – they are all very well-supported. You’ll find many help documents, tutorials, resources, and support from the community.

Issues with the QT Py ESP32-S2 board

One of the ways to help solve issues with the QT Py ESP32-S2 board that I came across was that you can factory reset this board. I also didn’t realize that you can use this board as a drive, and when you press the reset button on it twice, if it’s plugged into your computer, it will appear as a drive. Figure 14.31 shows the drive when it is opened...

What’s in the future?

You are now part of the future of wearables too! With your new making skills, you’ll join the wearable field and be able to contribute informed wearables, wearables with a purpose, to the wearable community. Hopefully, you’ll also explore alternative ways of making or using and mixing up components from other fields – for example, I’ve mashed together one of my QT Py circuit boards with these little ring terminals to create a version of the board (see Figure 14.37) that I can quickly get connected with croc clips:

Figure 14.37 – Adding your own inventive connections to the circuit boards you use

I started by soldering wires to the circuit board. Then, I stripped the wire ends and folded them over to create good connections. I pushed heat shrink onto the wire before pushing the wire end inside the ring terminal. There, I applied a small amount of flux to help the solder flow through, and I soldered...

Summary

Congratulations! You have now finished the book.

I hope you have found it an inspiring and, at times, challenging journey. You will be equipped to design sewable circuits using conductive fabrics and threads, as well as create circuits with sensors and outputs. You also worked to create a smart wearable using IoT for connecting to an online service with an ESP32-based board. Hopefully, you’ll be carrying around a small multimeter with you as you hunt for metallic fabrics.

You have followed a Design Innovation process and now have the tools to design your projects. There are templates and guides, along with questions to ask yourself when creating in this field.

This final chapter has links and references to other programs and applications you might want to try. It could be that you start to create your schematics in Fritzing or that you look at circuit design in Eagle. Whatever direction you decide to head in, remember that there are many support forums, tutorials...

References

The following references were referred to in this chapter or are suggested for further knowledge about the topics presented:

Ren, W., Sun, Y., Zhao, D., Aili, A., Zhang, S., Shi, C., ... & Yang, R. (2021). High-performance wearable thermoelectric generator with self-healing, recycling, and Lego-like reconfiguring capabilities. In Science advances, 7(7), eabe0586. https://www.science.org/doi/10.1126/sciadv.abe0586

Matsuhisa, N., Niu, S., O’Neill, S. J., Kang, J., Ochiai, Y., Katsumata, T., ... & Bao, Z. (2021). High-frequency and intrinsically stretchable polymer diodes. In Nature, 600(7888), 246-252.

de Medeiros, M. S., Goswami, D., Chanci, D., Moreno, C., & Martinez, R. V. (2021). Washable, breathable, and stretchable e-textiles wirelessly powered by omniphobic silk-based coils. In Nano Energy, 87, 106155. https://www.researchgate.net/profile/Debkalpa-Goswami/publication/351824432_Supporting_Information_Washable_Breathable_and_Stretchable_e...

Review questions

1. What are the benefits of documenting our projects?
2. Name three possible good ways you can troubleshoot your circuits.
3. What are some of the techniques we can use to bring other dimensions into our wearable designs?
4. Reflect on your learning throughout the book. What activities did you find the most helpful or useful for your wearable designs?
5. What next steps will you take to create wearable technology?
6. What does the future of wearables look like to you?