Designing Salt & Pepper Shakers
Designing Salt & Pepper Shakers for people with Arthritis
Duration: 9 days
Project Type: Rapid Prototyping, Product Design
Tools: Rhino, 3D Printer/3D Printing
Keywords: User Research, Elderly, Inclusive Design, Accessibility
Project Overview: Usually most cutlery, kitchen utensils and daily objects tend to forget people with arthritis while being designed. Though it might seem like a niche audience, it is pretty appalling to know that in the United States, around 53.2 million US adults, approximately 21.2% of adult population suffer from arthritis.
👀 For those who want a quick 2 minute glance, this is how the project went 👀
Problem Statement 🎯
What problem am I trying to solve?
The needs and constraints of people with disabilities (arthritis) are not considered while designing everyday products like kitchen cutlery, appliances etc.
Imagine finding it difficult to use any kitchen cutlery and depending on someone else to simply add salt to one's food. So, the minute I was given the brief to design salt and pepper shakers, I chose to find people who usually have difficulty using conventional salt & pepper such as people with arthritis.
So, where did it all begin?
Having been exposed to different minority groups like elderly people, people with disabilities etc. throughout my life, I developed an interest in inclusive and accessible design. I realised that disability had more to do with the design than the individuals themselves. I strongly believed that the design, rather than the individual, can create disabling or enabling environments. Thus, when given the brief of designing a salt and pepper shaker, I chose to go ahead with a minority group who might have difficulties using the conventional salt and pepper shakers. While researching about the different groups of people who have difficulty using the salt and pepper shakers, the group that struck out to me the most is - people with arthritis. While I have interacted briefly with an elderly with arthritis, I otherwise had no idea about the market size, the need for arthritis friendly products etc. Thus, my project began with understanding my target audience.
User Research 👤👤
Whose problem am I trying to solve?
People with Arthritis. 🦽
Arthritis, scientifically known as, Osteoarthritis is a degenerative joint condition, that causes pain, swelling and stiffness, ultimately affecting a person’s ability to move freely. Osteoarthritis affects the entire join including the different tissues around the joint and can be common in areas like the knees, hips, spine and hands.
As osteoarthritis is more prevalent in older people (about 70% are older than 55), global prevalence is expected to increase with the ageing of populations. Statistics state that around 53.2 million US adults, approximately 21.2% of adult population suffer from arthritis. Further, according to World Health Organization (WHO) data, nearly 9.6 percent of men and 18 percent of women aged over 60 years suffer from Osteoarthritis worldwide. As osteoarthritis is more prevalent in older people (about 70% are older than 55), global prevalence is expected to increase with the ageing of populations.
Thus, the global scale and market supports the viability of the product.
Now that I both my problem statement and my target users, how do I go about this project?
To break down the problem statement and understand my target audience better, I chose to use a mind map. Using a mind map helped me identify the nitty gritty details I had to consider for my project. It also helped me understand the problem at hand better and provided me with a clearer idea on how to proceed ahead.
What is the course of action? 🗓️
Just like Pheobe from F.R.I.E.N.D.S says, "I don't even have a Pla-", there isn't a step by step plan considering design is a messy process, but there were a few boxes to tick for this project such as:
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Understanding the functional aspect of conventional salt and pepper shakers
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The existing products designed for people with arthritis
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Hand movements people with arthritis are comfortable with
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Rapid Prototyping & Testing
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Testing functional prototypes
What is a salt & pepper shaker used for?
Traditional/Conventional Salt and Pepper shakers are used to both store salt/pepper and dispense it. The conventional way of doing so will be by shaking the product lightly or sometimes vigourously. However, the function of dispensing salt can be achieved by other mechanisms as well such as:
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squeezing
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pinching
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opening
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pushing & pulling
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rotating
What are some design considerations done while designing for people with arthritis?
By looking through the different products designed exclusively for people with arthritis, I recognised some key characteristics:
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handles having a large surface area for ease of grip
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products being larger in size but lighter in weight
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reduced hand movements
that can be incorporated into my design.
What are the hand actions/movements people with arthritis are comfortable with?
This activity of analysing the different hand movements people with arthritis are comfortable in, helped me in identifying the different mechanisms that can be used to dispense salt/pepper from the shakers without adding strain to one’s hands.
I sketched to visualise and explore a range of ideas, which helped in understanding potential forms and functions. 🎨
I created an Ideation Dump to capture various ideas. The initial phase involved sketching different forms and mechanisms for dispensing salt and pepper, based on research into arthritis-friendly products. This research guided the ideation process, and rough sketches allowed for rapid prototyping of different designs for later testing. I focused on a form that could serve as both a handle and a shaker, incorporating multiple finger grooves based on anthropometric data to ensure ergonomic efficiency. Additionally, I explored other forms, like a seashell model and designs with curves and grooves for better grip.
Ergonomic Study 🦾
How can we effectively study ergonomics to inform the design of our product?
The primary goal of this stage was understanding and testing forms and their ergonomics, which aided in the further development and design of this project.
To simplify and accelerate my physical ideation part of the project, I resorted to clay as a material. Since most of the forms I wished to test were organic, clay seemed to be the best material to use to test. With clay, I was able to test different shapes/forms and sizes and how they felt while grasping or squeezing to dispense salt/pepper. I even added a variety of materials like paper straws and skewer sticks to add elements to the physical ideation.
So the findings 👀?
By mapping out all the different mechanisms one could use to dispense salt & pepper, and the different pain points (literally, pain points), the simplest hand action to dispense salt was the squeeze mechanism. The squeeze mechanism involves hand actions that are recommended for people with arthritis as an exercise as well (yay, brownie points!)
Step 2: Delving deeper into ergonomics 🦾
I also, decided to compare different shapes of everyday products at home like tablet boxes, skincare boxes, cleaning products and even stitching/threading products (images below) to just get a better comprehensive understanding on forms and sizes.
I created mockups to test ergonomics...
To better understand the form and ergonomics, I created a paper model. This allowed me to evaluate and validate several design assumptions. I discovered that the finger grooves were too widely spaced, making the form uncomfortable to hold. Additionally, the holding surface was too small, which would be problematic for people with larger hands. The flat surface was also uncomfortable for the thumb to rest on. Furthermore, the design did not accommodate the squeeze mechanism, leading me to eliminate this form.
Step 3: Testing out Physical Ideations
I translated most of my sketches into simplified physical models for testing. Several ideas were eliminated based on my understanding of ergonomics and the mechanisms for dispensing salt and pepper. I selected a few models that utilized the squeeze mechanism and aligned with my ergonomic insights for further testing.
Design Outcome 🎬
How was the final outcome designed and tested?
I 3D modelled my design...
Creating a clay mockup was straightforward, but modeling it in 3D CAD software was much more complex. Determining precise dimensions for both the external structure and internal components required extensive calculations, research, and iterative experimentation. With assistance from digital resources like Google and ChatGPT, and some guesswork, I eventually derived a viable set of dimensions. However, true validation awaited a physical prototype.
I iterated the final 3D model multiple times due to various issues, such as making the sphere hollow and adding a dent. Deciding on the wall thickness without a physical reference was challenging, so I experimented with thicknesses ranging from 0.8mm to 3mm, ultimately settling on 1.2mm for economic and feasibility reasons for 3D printing. During this process, I also added a beak-like structure as a nozzle to enhance the product's aesthetics.
Creating multiple 3D Models
I iterated the final 3D model multiple times to address various issues. Challenges included making the sphere hollow, adding a dent, and determining wall thickness without a physical reference. The wall thickness was ultimately decided through trial and error. To enhance aesthetics, I designed the nozzle with a beak-like structure, which also serves as a functional nozzle for the product.
3D printing the prototype
TPU filament was chosen as the material due to its flexible nature which will suit the squeezing mechanism this product has. The prototype was printed in separate parts, requiring assembly with glue. For testing, a simple masking tape was used to hold the components together. The montage above showcases the structure and form of the prototype captured through various photographs.
Testing the 3D Prototype
During testing, the prototype was held together with tape and tested with fine salt, revealing several design shortcomings that needed adjustments. Key areas for improvement include:
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The nozzle, with a small slit for salt dispensing (2mm x 1mm), was too narrow, causing salt particles to clog and block the slit.
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The solid nozzle design made squeezing the product difficult.
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A dent on the opposite side of the nozzle required users to flip the entire product to dispense salt.
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Variation in thickness between the nozzle and the sphere body caused tearing during squeezing, necessitating uniform wall thickness.
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The solid base, while providing stability, hindered squeezing.
Learning about 3D printing
Post the printing process, I learnt about how the different types of infills can make a huge difference in the structure and flexibility of the product/prototype. Not specifying the infill percentage or type during 3D printing led to issues in the prototype. Post-printing, it became clear that 10-25% infill and a spiral pattern were needed for stability and flexibility. Though, this was just a prototype and the original product is to be made in silicon/flexible material, it is important for a prototype to mimic the feel and function of the final product. Since this was my first time 3D printing a product, this project served as a great learning opportunity in understanding the technicalities behind 3D Printing.
The Outcome 🎬
What was my final outcome for this brief?
Learnings & Reflection 🧠
What comes out of this journey?
Learning to work with physical limitations
This project marked my first experience working with metal as a material, offering a deep dive into metalworking processes. I learned to bend metal, angle grind, spot weld, and drill through metal pipes, gaining firsthand insights into metal properties. Given the project's tight 11-day timeframe, I quickly adapted and developed new skills. This rapid-paced environment introduced me to the concept of rapid prototyping, a pivotal skill in product design.
Getting familiar with 3D printing
This was also my first time using Rhino for 3D modeling. Throughout the project, I navigated the design process of creating a full-fledged physical product, involving multiple iterations. I learned to consider additional factors when designing inclusive physical products, such as understanding anthropometric data. The experience was a steep learning curve, enhancing my ability to design and model efficiently.
What would I do if I had more time?
This project was executed without direct input from the target user group, relying instead on data and measurements sourced from the internet due to time constraints. Moving forward, I intend to prioritize user engagement by conducting interviews to gain deeper insights into their perspectives. Usability testing will follow, allowing for a better understanding of the product's effectiveness for the intended audience. While functionality was the primary focus during this project, aesthetics and tactile experience were somewhat neglected. Given additional time, I aim to refine the Color, Material, and Finish (CMF) aspects of the product for enhanced appeal and user satisfaction.
My prototype pretty much failed. Sad, I know, but the project had to continue. So, I re-looked into my design and came up with a better one.
Due to time and resource constraints, the redesigned model could not be reprinted and tested. Instead, I remodeled the prototype based on insights from testing. This version features a hollow nozzle with uniform thickness to the sphere body. I repositioned the dent so the nozzle points towards the user when the product is on the table. To prevent clogging, I created a larger opening for dispensing salt. The next stages will involve 3D printing this mockup and testing it, specifying the infill percentage and type to mimic the final product. Ideally, the final product will be made of silicone to support the squeezing mechanism.
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Step 1: Mapping out the Hand Actions
I mimicked the steps of using a conventional/traditional salt and pepper shaker to grasp the sequence of actions. This was done to map the different hand movements and actions involved and to ultimately compare the different mechanisms that can be used to dispense salt/pepper.
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A tiny disclaimer
Salt and pepper shakers being arthritis-friendly might seem like a minor concern for those with arthritis, especially since they are advised to avoid high salt intake. However, given the brief of designing salt and pepper shakers, I wished to re-imagine how salt and pepper shakers would look like if they were designed to be inclusive for anyone with hand disabilities. Through this project, I hoped to highlight the importance of considering ease of use and ergonomic design for people with limited dexterity, which can be translated to other areas. Even if salt is not commonly used by people with arthritis, the design suggested could be translated to products used for storing and dispensing spices.
