This symposium will cover challenges related to materials and mechanics in haptics—that is, technologies that engage with the sense of touch—for human-machine interfaces. Human machine interfaces are increasingly pervasive as we move towards hyperconnectivity. They enable applications in surgical training and telerobotic surgery, medical devices for rehabilitation and behavior modification, education and training, and for other devices in virtual and augmented reality. Despite the importance of material properties and mechanical phenomena in determining the “feel” of objects in the real world, until recently, the tools of materials research have been underapplied to the development of haptic interfaces. Historically, haptic systems have been constructed using off-the-shelf materials and actuators which operate predominantly using well known physical phenomena. While these devices can provide feedback, often in the form of force, texture, motion, vibration, or temperature, and convey information (e.g., the haptic sensation one receives from a phone upon receipt of a text message), these sensations are often unlike the feeling of objects in the natural world. New phenomena in the field of materials and mechanics have much to contribute, particularly in the creation of systems that can render realistic, dynamic feedback. For example, the production of sensations associated with thermal conductivity, softness, roughness, stickiness, and sliminess cannot be rendered easily without exploiting new materials and mechanical phenomena. To do so requires a diverse class of materials that can change their properties—e.g., phase, oxidation state, modulus, adhesion, electrical and thermal conductivity, etc.—and which can do so in real time. Some classes of materials which can accomplish these transformations includes conductive and stimulus-responsive polymers, liquid-crystal elastomers, liquid metals, soft pneumatic actuators, and various types of active, microstructured surfaces. Along with haptics, the symposium is also open to other types of human-machine interfaces which are difficult to categorize and whose success requires innovation in materials science, broadly interpreted. This symposium represents a rare opportunity to bring together experts in materials chemistry, mechanics, electronics, robotics, computer science, and human psychophysics.