A workpiece unit includes a wafer, a tape stuck to the wafer, and an annular frame to which an outer circumferential edge of the tape is stuck and which has an opening defined centrally therein. The wafer is disposed in the opening in the annular frame and supported on the annular frame by the tape. An irreversible ultraviolet radiation detecting seal that discolors when irradiated with an ultraviolet radiation as an external stimulus is stuck to the annular frame.

A device for detecting exposure to light includes: a photo-responsive layer including a photochromic material; a skin-mimicking cover layer covering a first side of the photo-responsive layer; and an adhesive layer configured to couple a second side of the photo-responsive layer opposite the first side to a surface.

A device for detecting exposure to light includes: a photo-responsive layer including a photochromic material; a skin-mimicking cover layer covering a first side of the photo-responsive layer; and an adhesive layer configured to couple a second side of the photo-responsive layer opposite the first side to a surface.

A wearable apparatus for indicating a threshold amount of ultra-violet (UV) light has been received by a user and method of making the same are provided. In an embodiment, a wearable apparatus includes a first material and a second material. The second material includes a color changing material that changes color from a first color to a second color when exposed to a threshold level of UV light. The wearable apparatus is configured to be worn by a user in a place exposed to sunlight. The second color indicates that the user has been exposed to a threshold amount of UV light.

A wearable apparatus for indicating a threshold amount of ultra-violet (UV) light has been received by a user and method of making the same are provided. In an embodiment, a wearable apparatus includes a first material and a second material. The second material includes a color changing material that changes color from a first color to a second color when exposed to a threshold level of UV light. The wearable apparatus is configured to be worn by a user in a place exposed to sunlight. The second color indicates that the user has been exposed to a threshold amount of UV light.

A wearable UV indicator, methods of making and using same. The indicator includes a polymeric film substrate having a first side and a second side, an adhesive disposed on the first side of the substrate, and a readily understood user interface disposed on the second side of the substrate, wherein the user interface comprises a qualitative indicator of instantaneous intensity of solar ultraviolet irradiation and a qualitative indicator of accumulated exposure to solar ultraviolet radiation.

A wearable UV indicator, methods of making and using same. The indicator includes a polymeric film substrate having a first side and a second side, an adhesive disposed on the first side of the substrate, and a readily understood user interface disposed on the second side of the substrate, wherein the user interface comprises a qualitative indicator of instantaneous intensity of solar ultraviolet irradiation and a qualitative indicator of accumulated exposure to solar ultraviolet radiation.

The present disclosure teaches a UV dosimeter comprising a UV-sensitive layer and a barrier that protects the UV-sensitive layer. The barrier is permeable to oxygen but impermeable to water and, thus, protects the UV-sensitive layer from water while allowing exposure of the UV-sensitive layer to oxygen. The UV-sensitive layer is accessible to both UV radiation and visible light. The UV-sensitive layer comprises a mixture of a semiconductor material, a UV-oxidizable dye, a sacrificial electron donor, and a matrix material. The semiconductor material has a band gap that corresponds to photon energy of the UV radiation. The dye has both an oxidation state and a reduction state. The oxidation state of the dye is visibly distinguishable from the reduction state of the dye. The sacrificial electron donor oxidizes when exposed to UV radiation. The matrix provides structural integrity to the mixture.

The invention provides a light indicator (100) for use in evaluating melanopsin active radiation in a flux of light, the light indicator (100) comprising a first light indicator element (110) comprising a first light reflective element (112) and a second light indicator element (120) comprising a second light reflective element (122), the light reflecting elements (112,122) having different wavelength dependencies of the spectral reflectivity, wherein the light reflecting elements (112,122) are selected to provide the same intensity of reflected light of two or more different types of light irradiating on the light indicator elements (110,120), wherein the two or more different types of light have different spectral power distributions in the visible wavelength range but having the same ratios of the melanopic flux and the luminous flux, wherein the ratio of the melanopic flux and the luminous flux of light is defined as $\begin{array}{cc}\mathrm{MEF}=1.22\frac{{.Math.}_{=380}^{780}\mathrm{SPD}\left(\right)m\left(\right)}{{.Math.}_{=380}^{780}\mathrm{SPD}\left(\right)V\left(\right)}& \left(\mathrm{Eq}.1\right)\end{array}$
wherein SPD() is the spectral power distribution of the light, m() is the melanopic sensitivity function, and the V() is the photopic sensitivity.

The invention provides a light indicator (100) for use in evaluating melanopsin active radiation in a flux of light, the light indicator (100) comprising a first light indicator element (110) comprising a first light reflective element (112) and a second light indicator element (120) comprising a second light reflective element (122), the light reflecting elements (112,122) having different wavelength dependencies of the spectral reflectivity, wherein the light reflecting elements (112,122) are selected to provide the same intensity of reflected light of two or more different types of light irradiating on the light indicator elements (110,120), wherein the two or more different types of light have different spectral power distributions in the visible wavelength range but having the same ratios of the melanopic flux and the luminous flux, wherein the ratio of the melanopic flux and the luminous flux of light is defined as $\begin{array}{cc}\mathrm{MEF}=1.22\frac{{.Math.}_{=380}^{780}\mathrm{SPD}\left(\right)m\left(\right)}{{.Math.}_{=380}^{780}\mathrm{SPD}\left(\right)V\left(\right)}& \left(\mathrm{Eq}.1\right)\end{array}$
wherein SPD() is the spectral power distribution of the light, m() is the melanopic sensitivity function, and the V() is the photopic sensitivity.